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http://rosettacode.org/wiki/Matrix_transposition
Matrix transposition
Transpose an arbitrarily sized rectangular Matrix.
#F.C5.8Drmul.C3.A6
Fōrmulæ
originalMatrix := [[1, 1, 1, 1], [2, 4, 8, 16], [3, 9, 27, 81], [4, 16, 64, 256], [5, 25, 125, 625]]; transposedMatrix := TransposedMat(originalMatrix);
http://rosettacode.org/wiki/Maze_generation
Maze generation
This page uses content from Wikipedia. The original article was at Maze generation algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) Task Generate and show a maze, using the simple Depth-first search algorithm. Start at a random cell. Mark the current cell as visited, and get a list of its neighbors. For each neighbor, starting with a randomly selected neighbor: If that neighbor hasn't been visited, remove the wall between this cell and that neighbor, and then recurse with that neighbor as the current cell. Related tasks Maze solving.
#Phix
Phix
with javascript_semantics -- -- grid is eg for w=3,h=2: {"+---+---+---+", -- ("wall") -- "| ? | ? | ? |", -- ("cell") -- "+---+---+---+", -- ("wall") -- "| ? | ? | ? |", -- ("cell") -- "+---+---+---+", -- ("wall") -- ""} -- (for a trailing \n) -- -- note those ?(x,y) are at [y*2][x*4-1], and we navigate -- using y=2..2*h (+/-2), x=3..w*4-1 (+/-4) directly. -- constant w = 11, h = 8 sequence wall = join(repeat("+",w+1),"---")&"\n", cell = join(repeat("|",w+1)," ? ")&"\n", grid = split(join(repeat(wall,h+1),cell),'\n') procedure amaze(integer x, integer y) grid[y][x] = ' ' -- mark cell visited sequence p = shuffle({{x-4,y},{x,y+2},{x+4,y},{x,y-2}}) for i=1 to length(p) do integer {nx,ny} = p[i] if nx>1 and nx<w*4 and ny>1 and ny<=2*h and grid[ny][nx]='?' then integer mx = (x+nx)/2 grid[(y+ny)/2][mx-1..mx+1] = ' ' -- knock down wall amaze(nx,ny) end if end for end procedure function heads() return rand(2)=1 -- 50:50 true(1)/false(0) end function integer {x,y} = {(rand(w)*4)-1,rand(h)*2} amaze(x,y) -- mark start pos grid[y][x] = '*' -- add a random door (heads=rhs/lhs, tails=top/btm) if heads() then grid[rand(h)*2][heads()*w*4-1] = ' ' else x = rand(w)*4-1 grid[heads()*h*2+1][x-1..x+1] = ' ' end if printf(1,"%s\n",join(grid,'\n'))
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#Phix
Phix
with javascript_semantics function map_range(atom s, a1, a2, b1, b2) return b1+(s-a1)*(b2-b1)/(a2-a1) end function for i=0 to 10 by 2 do printf(1,"%2d : %g\n",{i,map_range(i,0,10,-1,0)}) end for
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#PicoLisp
PicoLisp
(scl 1)   (de mapRange (Val A1 A2 B1 B2) (+ B1 (*/ (- Val A1) (- B2 B1) (- A2 A1))) )     (for Val (range 0 10.0 1.0) (prinl (format (mapRange Val 0 10.0 -1.0 0) *Scl) ) )
http://rosettacode.org/wiki/MD5
MD5
Task Encode a string using an MD5 algorithm.   The algorithm can be found on   Wikipedia. Optionally, validate your implementation by running all of the test values in   IETF RFC (1321)   for MD5. Additionally,   RFC 1321   provides more precise information on the algorithm than the Wikipedia article. Warning:   MD5 has known weaknesses, including collisions and forged signatures.   Users may consider a stronger alternative when doing production-grade cryptography, such as SHA-256 (from the SHA-2 family), or the upcoming SHA-3. If the solution on this page is a library solution, see   MD5/Implementation   for an implementation from scratch.
#Octave
Octave
s = "The quick brown fox jumped over the lazy dog's back"; hash = md5sum(s, true); disp(hash)
http://rosettacode.org/wiki/Mandelbrot_set
Mandelbrot set
Mandelbrot set You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw the Mandelbrot set. Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
#Emacs_Lisp
Emacs Lisp
; === Mandelbrot ============================================   (setq mandel-size (cons 76 34)) (setq xmin -2) (setq xmax .5) (setq ymin -1.2) (setq ymax 1.2) (setq max-iter 20)   (defun mandel-iter-point (x y) "Run the actual iteration for each point." (let ((xp 0) (yp 0) (it 0) (xt 0)) (while (and (< (+ (* xp xp) (* yp yp)) 4) (< it max-iter)) (setq xt (+ (* xp xp) (* -1 yp yp) x)) (setq yp (+ (* 2 xp yp) y)) (setq xp xt) (setq it (1+ it))) it))   (defun mandel-iter (p) "Return string for point based on whether inside/outside the set." (let ((it (mandel-iter-point (car p) (cdr p)))) (if (= it max-iter) "*" "-")))   (defun mandel-pos (x y) "Convert screen coordinates to input coordinates." (let ((xp (+ xmin (* (- xmax xmin) (/ (float x) (car mandel-size))))) (yp (+ ymin (* (- ymax ymin) (/ (float y) (cdr mandel-size)))))) (cons xp yp)))   (defun mandel () "Plot the Mandelbrot set." (dotimes (y (cdr mandel-size)) (dotimes (x (car mandel-size)) (if (= x 0) (insert(format "\n%s" (mandel-iter (mandel-pos x y)))) (insert(format "%s" (mandel-iter (mandel-pos x y))))))))   (mandel)
http://rosettacode.org/wiki/Magic_squares_of_odd_order
Magic squares of odd order
A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers are usually (but not always) the first   N2   positive integers. A magic square whose rows and columns add up to a magic number but whose main diagonals do not, is known as a semimagic square. 8 1 6 3 5 7 4 9 2 Task For any odd   N,   generate a magic square with the integers   1 ──► N,   and show the results here. Optionally, show the magic number. You should demonstrate the generator by showing at least a magic square for   N = 5. Related tasks Magic squares of singly even order Magic squares of doubly even order See also MathWorld™ entry: Magic_square Odd Magic Squares (1728.org)
#Pascal
Pascal
PROGRAM magic; (* Magic squares of odd order *) CONST n=9; VAR i,j :INTEGER; BEGIN (*magic*) WRITELN('The square order is: ',n); FOR i:=1 TO n DO BEGIN FOR j:=1 TO n DO WRITE((i*2-j+n-1) MOD n*n + (i*2+j-2) MOD n+1:5); WRITELN END; WRITELN('The magic number is: ',n*(n*n+1) DIV 2) END (*magic*).
http://rosettacode.org/wiki/Matrix_multiplication
Matrix multiplication
Task Multiply two matrices together. They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
#GAP
GAP
# Built-in A := [[1, 2], [3, 4], [5, 6], [7, 8]]; B := [[1, 2, 3], [4, 5, 6]];   PrintArray(A); # [ [ 1, 2 ], # [ 3, 4 ], # [ 5, 6 ], # [ 7, 8 ] ]   PrintArray(B); # [ [ 1, 2, 3 ], # [ 4, 5, 6 ] ]   PrintArray(A * B); # [ [ 9, 12, 15 ], # [ 19, 26, 33 ], # [ 29, 40, 51 ], # [ 39, 54, 69 ] ]
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#PHP
PHP
<?php function A($k,$x1,$x2,$x3,$x4,$x5) { $b = function () use (&$b,&$k,$x1,$x2,$x3,$x4) { return A(--$k,$b,$x1,$x2,$x3,$x4); }; return $k <= 0 ? $x4() + $x5() : $b(); }   echo A(10, function () { return 1; }, function () { return -1; }, function () { return -1; }, function () { return 1; }, function () { return 0; }) . "\n"; ?>
http://rosettacode.org/wiki/Matrix_transposition
Matrix transposition
Transpose an arbitrarily sized rectangular Matrix.
#GAP
GAP
originalMatrix := [[1, 1, 1, 1], [2, 4, 8, 16], [3, 9, 27, 81], [4, 16, 64, 256], [5, 25, 125, 625]]; transposedMatrix := TransposedMat(originalMatrix);
http://rosettacode.org/wiki/Maze_generation
Maze generation
This page uses content from Wikipedia. The original article was at Maze generation algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) Task Generate and show a maze, using the simple Depth-first search algorithm. Start at a random cell. Mark the current cell as visited, and get a list of its neighbors. For each neighbor, starting with a randomly selected neighbor: If that neighbor hasn't been visited, remove the wall between this cell and that neighbor, and then recurse with that neighbor as the current cell. Related tasks Maze solving.
#PHP
PHP
<?php class Maze { protected $width; protected $height; protected $grid; protected $path; protected $horWalls; protected $vertWalls; protected $dirs; protected $isDebug;   public function __construct($x, $y, $debug = false) { $this->width = $x; $this->height = $y; $this->path = []; $this->dirs = [ [0, -1], [0, 1], [-1, 0], [1, 0]]; // array of coordinates of N,S,W,E $this->horWalls = []; // list of removed horizontal walls (---+) $this->vertWalls = [];// list of removed vertical walls (|) $this->isDebug = $debug; // debug flag   // generate the maze: $this->generate(); }   protected function generate() { $this->initMaze(); // init the stack and an unvisited grid // start from a random cell and then proceed recursively $this->walk(mt_rand(0, $this->width-1), mt_rand(0, $this->height-1)); }   /** * Actually prints the Maze, on stdOut. Put in a separate method to allow extensibility * For simplicity sake doors are positioned on the north wall and east wall */ public function printOut() { $this->log("Horizontal walls: %s", json_encode($this->horWalls)); $this->log("Vertical walls: %s", json_encode($this->vertWalls));   $northDoor = mt_rand(0,$this->width-1); $eastDoor = mt_rand(0, $this->height-1);   $str = '+'; for ($i=0;$i<$this->width;$i++) { $str .= ($northDoor == $i) ? ' +' : '---+'; } $str .= PHP_EOL; for ($i=0; $i<$this->height; $i++) {   for ($j=0; $j<$this->width; $j++) { $str .= (!empty($this->vertWalls[$j][$i]) ? $this->vertWalls[$j][$i] : '| '); } $str .= ($i == $eastDoor ? ' ' : '|').PHP_EOL.'+'; for ($j=0; $j<$this->width; $j++) { $str .= (!empty($this->horWalls[$j][$i]) ? $this->horWalls[$j][$i] : '---+'); } $str .= PHP_EOL; } echo $str; }   /** * Logs to stdOut if debug flag is enabled */ protected function log(...$params) { if ($this->isDebug) { echo vsprintf(array_shift($params), $params).PHP_EOL; } }   private function walk($x, $y) { $this->log('Entering cell %d,%d', $x, $y); // mark current cell as visited $this->grid[$x][$y] = true; // add cell to path $this->path[] = [$x, $y]; // get list of all neighbors $neighbors = $this->getNeighbors($x, $y); $this->log("Valid neighbors: %s", json_encode($neighbors));   if(empty($neighbors)) { // Dead end, we need now to backtrack, if there's still any cell left to be visited $this->log("Start backtracking along path: %s", json_encode($this->path)); array_pop($this->path); if (!empty($this->path)) { $next = array_pop($this->path); return $this->walk($next[0], $next[1]); } } else { // randomize neighbors, as per request shuffle($neighbors);   foreach ($neighbors as $n) { $nextX = $n[0]; $nextY = $n[1]; if ($nextX == $x) { $wallY = max($nextY, $y); $this->log("New cell is on the same column (%d,%d), removing %d, (%d-1) horizontal wall", $nextX, $nextY, $x, $wallY); $this->horWalls[$x][min($nextY, $y)] = " +"; } if ($nextY == $y) { $wallX = max($nextX, $x); $this->log("New cell is on the same row (%d,%d), removing %d,%d vertical wall", $nextX, $nextY, $wallX, $y); $this->vertWalls[$wallX][$y] = " "; } return $this->walk($nextX, $nextY); } } }   /** * Initialize an empty grid of $width * $height dimensions */ private function initMaze() { for ($i=0;$i<$this->width;$i++) { for ($j = 0;$j<$this->height;$j++) { $this->grid[$i][$j] = false; } } }   /** * @param int $x * @param int $y * @return array */ private function getNeighbors($x, $y) { $neighbors = []; foreach ($this->dirs as $dir) { $nextX = $dir[0] + $x; $nextY = $dir[1] + $y; if (($nextX >= 0 && $nextX < $this->width && $nextY >= 0 && $nextY < $this->height) && !$this->grid[$nextX][$nextY]) { $neighbors[] = [$nextX, $nextY]; } } return $neighbors; } }   $maze = new Maze(10,10); $maze->printOut();
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#PL.2FI
PL/I
  map: procedure options (main); /* 24/11/2011 */ declare (a1, a2, b1, b2) float; declare d fixed decimal (3,1);   do d = 0 to 10 by 0.9, 10; put skip edit ( d, ' maps to ', map(0, 10, -1, 0, d) ) (f(5,1), a, f(10,6)); end;   map: procedure (a1, a2, b1, b2, s) returns (float); declare (a1, a2, b1, b2, s) float; return (b1 + (s - a1)*(b2 - b1) / (a2 - a1) ); end map; end map;  
http://rosettacode.org/wiki/MD5
MD5
Task Encode a string using an MD5 algorithm.   The algorithm can be found on   Wikipedia. Optionally, validate your implementation by running all of the test values in   IETF RFC (1321)   for MD5. Additionally,   RFC 1321   provides more precise information on the algorithm than the Wikipedia article. Warning:   MD5 has known weaknesses, including collisions and forged signatures.   Users may consider a stronger alternative when doing production-grade cryptography, such as SHA-256 (from the SHA-2 family), or the upcoming SHA-3. If the solution on this page is a library solution, see   MD5/Implementation   for an implementation from scratch.
#Ol
Ol
  (import (otus ffi)) (define libcrypto (load-dynamic-library "libcrypto.so.1.0.0")) (define MD5 (libcrypto type-vptr "MD5" type-string fft-unsigned-long type-string))  
http://rosettacode.org/wiki/Mandelbrot_set
Mandelbrot set
Mandelbrot set You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw the Mandelbrot set. Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
#Erlang
Erlang
  -module(mandelbrot).   -export([test/0]).   magnitude(Z) -> R = complex:real(Z), I = complex:imaginary(Z), R * R + I * I.   mandelbrot(A, MaxI, Z, I) -> case (I < MaxI) and (magnitude(Z) < 2.0) of true -> NZ = complex:add(complex:mult(Z, Z), A), mandelbrot(A, MaxI, NZ, I + 1); false -> case I of MaxI -> $*; _ -> $ end end.   test() -> lists:map( fun(S) -> io:format("~s",[S]) end, [ [ begin Z = complex:make(X, Y), mandelbrot(Z, 50, Z, 1) end || X <- seq_float(-2, 0.5, 0.0315) ] ++ "\n" || Y <- seq_float(-1,1, 0.05) ] ), ok.   % ************************************************** % Copied from https://gist.github.com/andruby/241489 % **************************************************   seq_float(Min, Max, Inc, Counter, Acc) when (Counter*Inc + Min) >= Max -> lists:reverse([Max|Acc]); seq_float(Min, Max, Inc, Counter, Acc) -> seq_float(Min, Max, Inc, Counter+1, [Inc * Counter + Min|Acc]). seq_float(Min, Max, Inc) -> seq_float(Min, Max, Inc, 0, []).   % **************************************************  
http://rosettacode.org/wiki/Magic_squares_of_odd_order
Magic squares of odd order
A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers are usually (but not always) the first   N2   positive integers. A magic square whose rows and columns add up to a magic number but whose main diagonals do not, is known as a semimagic square. 8 1 6 3 5 7 4 9 2 Task For any odd   N,   generate a magic square with the integers   1 ──► N,   and show the results here. Optionally, show the magic number. You should demonstrate the generator by showing at least a magic square for   N = 5. Related tasks Magic squares of singly even order Magic squares of doubly even order See also MathWorld™ entry: Magic_square Odd Magic Squares (1728.org)
#Perl
Perl
 
http://rosettacode.org/wiki/Magic_squares_of_odd_order
Magic squares of odd order
A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers are usually (but not always) the first   N2   positive integers. A magic square whose rows and columns add up to a magic number but whose main diagonals do not, is known as a semimagic square. 8 1 6 3 5 7 4 9 2 Task For any odd   N,   generate a magic square with the integers   1 ──► N,   and show the results here. Optionally, show the magic number. You should demonstrate the generator by showing at least a magic square for   N = 5. Related tasks Magic squares of singly even order Magic squares of doubly even order See also MathWorld™ entry: Magic_square Odd Magic Squares (1728.org)
#Phix
Phix
with javascript_semantics function magic_square(integer n) if mod(n,2)!=1 or n<1 then return false end if sequence square = repeat(repeat(0,n),n) for i=1 to n do for j=1 to n do square[i,j] = n*mod(2*i-j+n-1,n) + mod(2*i+j-2,n) + 1 end for end for return square end function procedure check(sequence sq) integer n = length(sq) integer magic = n*(n*n+1)/2 integer bd=0, fd=0 for i=1 to length(sq) do if sum(sq[i])!=magic then ?9/0 end if if sum(columnize(sq,i))!=magic then ?9/0 end if bd += sq[i,i] fd += sq[n-i+1,n-i+1] end for if bd!=magic or fd!=magic then ?9/0 end if end procedure for i=1 to 7 by 2 do sequence square = magic_square(i) printf(1,"maqic square of order %d, sum: %d\n", {i,sum(square[i])}) string fmt = sprintf("%%%dd",length(sprintf("%d",i*i))) pp(square,{pp_Nest,1,pp_IntFmt,fmt,pp_StrFmt,3,pp_IntCh,false,pp_Pause,0}) check(square) end for
http://rosettacode.org/wiki/Matrix_multiplication
Matrix multiplication
Task Multiply two matrices together. They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
#Generic
Generic
  generic coordinaat { ecs uuii   coordinaat() { ecs=+a uuii=+a}   coordinaat(ecs_set uuii_set) { ecs = ecs_set uuii=uuii_set }   operaator<(c) { iph ecs < c.ecs return troo iph c.ecs < ecs return phals iph uuii < c.uuii return troo return phals }   operaator==(connpair) // eecuuols and not eecuuols deriiu phronn operaator< { iph this < connpair return phals iph connpair < this return phals return troo }   operaator!=(connpair) { iph this < connpair return troo iph connpair < this return troo return phals }   too_string() { return "(" + ecs.too_string() + "," + uuii.too_string() + ")" }   print() { str = too_string() str.print() }   println() { str = too_string() str.println() } }   generic nnaatrics { s // this is a set of coordinaat/ualioo pairs. iteraator // this field holds an iteraator phor the nnaatrics.   nnaatrics() // no parameters required phor nnaatrics construction. { s = nioo set() // create a nioo set of coordinaat/ualioo pairs. iteraator = nul // the iteraator is initially set to nul. }   nnaatrics(copee) // copee the nnaatrics. { s = nioo set() // create a nioo set of coordinaat/ualioo pairs. iteraator = nul // the iteraator is initially set to nul.   r = copee.rouus c = copee.cols i = 0 uuiil i < r { j = 0 uuiil j < c { this[i j] = copee[i j] j++ } i++ } }   begin { get { return s.begin } } // property: used to commence manual iteraashon.   end { get { return s.end } } // property: used to dephiin the end itenn of iteraashon   operaator<(a) // les than operaator is corld bii the avl tree algorithnns { // this operaator innpliis phor instance that you could potenshalee hav sets ou nnaatricss. iph cees < a.cees // connpair the cee sets phurst. return troo els iph a.cees < cees return phals els // the cee sets are eecuuol thairphor connpair nnaatrics elennents. { phurst1 = begin lahst1 = end phurst2 = a.begin lahst2 = a.end   uuiil phurst1 != lahst1 && phurst2 != lahst2 { iph phurst1.daata.ualioo < phurst2.daata.ualioo return troo els { iph phurst2.daata.ualioo < phurst1.daata.ualioo return phals els { phurst1 = phurst1.necst phurst2 = phurst2.necst } } }   return phals } }   operaator==(connpair) // eecuuols and not eecuuols deriiu phronn operaator< { iph this < connpair return phals iph connpair < this return phals return troo }   operaator!=(connpair) { iph this < connpair return troo iph connpair < this return troo return phals }     operaator[cee_a cee_b] // this is the nnaatrics indexer. { set { trii { s >> nioo cee_ualioo(new coordinaat(cee_a cee_b)) } catch {} s << nioo cee_ualioo(new coordinaat(nioo integer(cee_a) nioo integer(cee_b)) ualioo) } get { d = s.get(nioo cee_ualioo(new coordinaat(cee_a cee_b))) return d.ualioo } }   operaator>>(coordinaat) // this operaator reennoous an elennent phronn the nnaatrics. { s >> nioo cee_ualioo(coordinaat) return this }   iteraat() // and this is how to iterate on the nnaatrics. { iph iteraator.nul() { iteraator = s.lepht_nnohst iph iteraator == s.heder return nioo iteraator(phals nioo nun()) els return nioo iteraator(troo iteraator.daata.ualioo) } els { iteraator = iteraator.necst   iph iteraator == s.heder { iteraator = nul return nioo iteraator(phals nioo nun()) } els return nioo iteraator(troo iteraator.daata.ualioo) } }   couunt // this property returns a couunt ou elennents in the nnaatrics. { get { return s.couunt } }   ennptee // is the nnaatrics ennptee? { get { return s.ennptee } }     lahst // returns the ualioo of the lahst elennent in the nnaatrics. { get { iph ennptee throuu "ennptee nnaatrics" els return s.lahst.ualioo } }   too_string() // conuerts the nnaatrics too aa string { return s.too_string() }   print() // prints the nnaatrics to the consohl. { out = too_string() out.print() }   println() // prints the nnaatrics as a liin too the consohl. { out = too_string() out.println() }   cees // return the set ou cees ou the nnaatrics (a set of coordinaats). { get { k = nioo set() phor e : s k << e.cee return k } }   operaator+(p) { ouut = nioo nnaatrics() phurst1 = begin lahst1 = end phurst2 = p.begin lahst2 = p.end uuiil phurst1 != lahst1 && phurst2 != lahst2 { ouut[phurst1.daata.cee.ecs phurst1.daata.cee.uuii] = phurst1.daata.ualioo + phurst2.daata.ualioo phurst1 = phurst1.necst phurst2 = phurst2.necst } return ouut }   operaator-(p) { ouut = nioo nnaatrics() phurst1 = begin lahst1 = end phurst2 = p.begin lahst2 = p.end uuiil phurst1 != lahst1 && phurst2 != lahst2 { ouut[phurst1.daata.cee.ecs phurst1.daata.cee.uuii] = phurst1.daata.ualioo - phurst2.daata.ualioo phurst1 = phurst1.necst phurst2 = phurst2.necst } return ouut }   rouus { get { r = +a phurst1 = begin lahst1 = end uuiil phurst1 != lahst1 { iph r < phurst1.daata.cee.ecs r = phurst1.daata.cee.ecs phurst1 = phurst1.necst } return r + +b } }   cols { get { c = +a phurst1 = begin lahst1 = end uuiil phurst1 != lahst1 { iph c < phurst1.daata.cee.uuii c = phurst1.daata.cee.uuii phurst1 = phurst1.necst } return c + +b } }   operaator*(o) { iph cols != o.rouus throw "rouus-cols nnisnnatch" reesult = nioo nnaatrics() rouu_couunt = rouus colunn_couunt = o.cols loop = cols i = +a uuiil i < rouu_couunt { g = +a uuiil g < colunn_couunt { sunn = +a.a h = +a uuiil h < loop { a = this[i h]   b = o[h g] nn = a * b sunn = sunn + nn h++ }   reesult[i g] = sunn   g++ } i++ } return reesult }   suuop_rouus(a b) { c = cols i = 0 uuiil u < cols { suuop = this[a i] this[a i] = this[b i] this[b i] = suuop i++ } }   suuop_colunns(a b) { r = rouus i = 0 uuiil i < rouus { suuopp = this[i a] this[i a] = this[i b] this[i b] = suuop i++ } }   transpohs { get { reesult = new nnaatrics()   r = rouus c = cols i=0 uuiil i < r { g = 0 uuiil g < c { reesult[g i] = this[i g] g++ } i++ }   return reesult } }   deternninant { get { rouu_couunt = rouus colunn_count = cols   if rouu_couunt != colunn_count throw "not a scuuair nnaatrics"   if rouu_couunt == 0 throw "the nnaatrics is ennptee"   if rouu_couunt == 1 return this[0 0]   if rouu_couunt == 2 return this[0 0] * this[1 1] - this[0 1] * this[1 0]   temp = nioo nnaatrics()   det = 0.0 parity = 1.0   j = 0 uuiil j < rouu_couunt { k = 0 uuiil k < rouu_couunt-1 { skip_col = phals   l = 0 uuiil l < rouu_couunt-1 { if l == j skip_col = troo   if skip_col n = l + 1 els n = l   temp[k l] = this[k + 1 n] l++ } k++ }   det = det + parity * this[0 j] * temp.deeternninant   parity = 0.0 - parity j++ }   return det } }   ad_rouu(a b) { c = cols i = 0 uuiil i < c { this[a i] = this[a i] + this[b i] i++ } }   ad_colunn(a b) { c = rouus i = 0 uuiil i < c { this[i a] = this[i a] + this[i b] i++ } }   subtract_rouu(a b) { c = cols i = 0 uuiil i < c { this[a i] = this[a i] - this[b i] i++ } }   subtract_colunn(a b) { c = rouus i = 0 uuiil i < c { this[i a] = this[i a] - this[i b] i++ } }   nnultiplii_rouu(rouu scalar) { c = cols i = 0 uuiil i < c { this[rouu i] = this[rouu i] * scalar i++ } }   nnultiplii_colunn(colunn scalar) { r = rouus i = 0 uuiil i < r { this[i colunn] = this[i colunn] * scalar i++ } }   diuiid_rouu(rouu scalar) { c = cols i = 0 uuiil i < c { this[rouu i] = this[rouu i] / scalar i++ } }   diuiid_colunn(colunn scalar) { r = rouus i = 0 uuiil i < r { this[i colunn] = this[i colunn] / scalar i++ } }   connbiin_rouus_ad(a b phactor) { c = cols i = 0 uuiil i < c { this[a i] = this[a i] + phactor * this[b i] i++ } }   connbiin_rouus_subtract(a b phactor) { c = cols i = 0 uuiil i < c { this[a i] = this[a i] - phactor * this[b i] i++ } }   connbiin_colunns_ad(a b phactor) { r = rouus i = 0 uuiil i < r { this[i a] = this[i a] + phactor * this[i b] i++ } }   connbiin_colunns_subtract(a b phactor) { r = rouus i = 0 uuiil i < r { this[i a] = this[i a] - phactor * this[i b] i++ } }   inuers { get { rouu_couunt = rouus colunn_couunt = cols   iph rouu_couunt != colunn_couunt throw "nnatrics not scuuair"   els iph rouu_couunt == 0 throw "ennptee nnatrics"   els iph rouu_couunt == 1 { r = nioo nnaatrics() r[0 0] = 1.0 / this[0 0] return r }   gauss = nioo nnaatrics(this)   i = 0 uuiil i < rouu_couunt { j = 0 uuiil j < rouu_couunt { iph i == j   gauss[i j + rouu_couunt] = 1.0 els gauss[i j + rouu_couunt] = 0.0 j++ }   i++ }   j = 0 uuiil j < rouu_couunt { iph gauss[j j] == 0.0 { k = j + 1   uuiil k < rouu_couunt { if gauss[k j] != 0.0 {gauss.nnaat.suuop_rouus(j k) break } k++ }   if k == rouu_couunt throw "nnatrics is singioolar" }   phactor = gauss[j j] iph phactor != 1.0 gauss.diuiid_rouu(j phactor)   i = j+1 uuiil i < rouu_couunt { gauss.connbiin_rouus_subtract(i j gauss[i j]) i++ }   j++ }   i = rouu_couunt - 1 uuiil i > 0 { k = i - 1 uuiil k >= 0 { gauss.connbiin_rouus_subtract(k i gauss[k i]) k-- } i-- }   reesult = nioo nnaatrics()   i = 0 uuiil i < rouu_couunt { j = 0 uuiil j < rouu_couunt { reesult[i j] = gauss[i j + rouu_couunt] j++ } i++ }   return reesult } }   }  
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#PicoLisp
PicoLisp
(de a (K X1 X2 X3 X4 X5) (let (@K (cons K) B (cons)) # Explicit frame (set B (curry (@K B X1 X2 X3 X4) () (a (dec @K) (car B) X1 X2 X3 X4) ) ) (if (gt0 (car @K)) ((car B)) (+ (X4) (X5))) ) )   (a 10 '(() 1) '(() -1) '(() -1) '(() 1) '(() 0))
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#PL.2FI
PL/I
morb: proc options (main) reorder; dcl sysprint file; put skip list(a((10), lambda1, lambdam1, lambdam1, lambda0, lambda0)); a: proc(k, x1, x2, x3, x4, x5) returns(fixed bin (31)) recursive; dcl k fixed bin (31); dcl (x1, x2, x3, x4, x5) entry returns(fixed bin (31)); b: proc returns(fixed bin(31)) recursive; k = k - 1; return(a((k), b, x1, x2, x3, x4)); end b; if k <= 0 then return(x4 + x5); else return(b); end a; lambdam1: proc returns(fixed bin (31)); return(-1); end lambdam1; lambda0: proc returns(fixed bin (31)); return(1); end lambda0; lambda1: proc returns(fixed bin (31)); return(1); end lambda1; end morb;
http://rosettacode.org/wiki/Matrix_transposition
Matrix transposition
Transpose an arbitrarily sized rectangular Matrix.
#Go
Go
package main   import ( "fmt"   "gonum.org/v1/gonum/mat" )   func main() { m := mat.NewDense(2, 3, []float64{ 1, 2, 3, 4, 5, 6, }) fmt.Println(mat.Formatted(m)) fmt.Println() fmt.Println(mat.Formatted(m.T())) }
http://rosettacode.org/wiki/Maze_generation
Maze generation
This page uses content from Wikipedia. The original article was at Maze generation algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) Task Generate and show a maze, using the simple Depth-first search algorithm. Start at a random cell. Mark the current cell as visited, and get a list of its neighbors. For each neighbor, starting with a randomly selected neighbor: If that neighbor hasn't been visited, remove the wall between this cell and that neighbor, and then recurse with that neighbor as the current cell. Related tasks Maze solving.
#Picat
Picat
main => gen_maze(8,8).   main([RStr,CStr]) => MaxR = to_int(RStr), MaxC = to_int(CStr), gen_maze(MaxR,MaxC).   gen_maze(MaxR,MaxC) => Maze = new_array(MaxR,MaxC), foreach (R in 1..MaxR, C in 1..MaxC) Maze[R,C] = 0 end, gen_maze(Maze,MaxR,MaxC,1,1), display_maze(Maze,MaxR,MaxC).   gen_maze(Maze,MaxR,MaxC,R,C) => Dirs = shuffle([left, right, up, down]), foreach (Dir in Dirs) dir(Dir,Dr,Dc,B,OB), R1 := R+Dr, C1 := C+Dc, if (R1 >= 1 && R1 =< MaxR && C1 >= 1 && C1 =< MaxC && Maze[R1,C1] == 0) then Maze[R,C] := Maze[R,C] \/ B, Maze[R1,C1] := Maze[R1,C1] \/ OB, gen_maze(Maze,MaxR,MaxC,R1,C1) end end.   % dir(direction, Dr, Dc, Bit, OppBit) dir(left, 0, -1, 1, 2). dir(right, 0, 1, 2, 1). dir(up, -1, 0, 4, 8). dir(down, 1, 0, 8, 4).   shuffle(Arr) = Res => foreach (_ in 1..10) I1 = random() mod 4 + 1, I2 = random() mod 4 + 1, T := Arr[I1], Arr[I1] := Arr[I2], Arr[I2] := T end, Res = Arr.   display_maze(Maze,MaxR,MaxC) => foreach (R in 1..MaxR) foreach (C in 1..MaxC) printf("%s", cond(Maze[R,C] /\ 4 == 0, "+---", "+ ")) end, println("+"), foreach (C in 1..MaxC) printf("%s", cond(Maze[R,C] /\ 1 == 0, "| ", " ")), end, println("|") end, foreach (C in 1..MaxC) print("+---") end, println("+").  
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#PowerShell
PowerShell
  function Group-Range { [CmdletBinding()] [OutputType([PSCustomObject])] Param ( [Parameter(Mandatory=$true, Position=0)] [ValidateCount(2,2)] [double[]] $Range1,   [Parameter(Mandatory=$true, Position=1)] [ValidateCount(2,2)] [double[]] $Range2,   [Parameter(Mandatory=$true, ValueFromPipeline=$true, Position=2)] [double] $Map )   Process { foreach ($number in $Map) { [PSCustomObject]@{ Index = $number Mapping = $Range2[0] + ($number - $Range1[0]) * ($Range2[0] - $Range2[1]) / ($Range1[0] - $Range1[1]) } } } }  
http://rosettacode.org/wiki/MD5
MD5
Task Encode a string using an MD5 algorithm.   The algorithm can be found on   Wikipedia. Optionally, validate your implementation by running all of the test values in   IETF RFC (1321)   for MD5. Additionally,   RFC 1321   provides more precise information on the algorithm than the Wikipedia article. Warning:   MD5 has known weaknesses, including collisions and forged signatures.   Users may consider a stronger alternative when doing production-grade cryptography, such as SHA-256 (from the SHA-2 family), or the upcoming SHA-3. If the solution on this page is a library solution, see   MD5/Implementation   for an implementation from scratch.
#OpenEdge.2FProgress
OpenEdge/Progress
MESSAGE 1 STRING( HEX-ENCODE( MD5-DIGEST( "" ) ) ) SKIP 2 STRING( HEX-ENCODE( MD5-DIGEST( "a" ) ) ) SKIP 3 STRING( HEX-ENCODE( MD5-DIGEST( "abc" ) ) ) SKIP 4 STRING( HEX-ENCODE( MD5-DIGEST( "message digest" ) ) ) SKIP 5 STRING( HEX-ENCODE( MD5-DIGEST( "abcdefghijklmnopqrstuvwxyz" ) ) ) SKIP 6 STRING( HEX-ENCODE( MD5-DIGEST( "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" ) ) ) SKIP 7 STRING( HEX-ENCODE( MD5-DIGEST( "12345678901234567890123456789012345678901234567890123456789012345678901234567890" ) ) ) VIEW-AS ALERT-BOX
http://rosettacode.org/wiki/Mandelbrot_set
Mandelbrot set
Mandelbrot set You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw the Mandelbrot set. Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
#ERRE
ERRE
  PROGRAM MANDELBROT   !$KEY !$INCLUDE="PC.LIB"   BEGIN   SCREEN(7) GR_WINDOW(-2,1.5,2,-1.5) FOR X0=-2 TO 2 STEP 0.01 DO FOR Y0=-1.5 TO 1.5 STEP 0.01 DO X=0 Y=0   ITERATION=0 MAX_ITERATION=223   WHILE (X*X+Y*Y<=(2*2) AND ITERATION<MAX_ITERATION) DO X_TEMP=X*X-Y*Y+X0 Y=2*X*Y+Y0   X=X_TEMP   ITERATION=ITERATION+1 END WHILE   IF ITERATION<>MAX_ITERATION THEN C=ITERATION ELSE C=0 END IF   PSET(X0,Y0,C) END FOR END FOR END PROGRAM  
http://rosettacode.org/wiki/Magic_squares_of_odd_order
Magic squares of odd order
A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers are usually (but not always) the first   N2   positive integers. A magic square whose rows and columns add up to a magic number but whose main diagonals do not, is known as a semimagic square. 8 1 6 3 5 7 4 9 2 Task For any odd   N,   generate a magic square with the integers   1 ──► N,   and show the results here. Optionally, show the magic number. You should demonstrate the generator by showing at least a magic square for   N = 5. Related tasks Magic squares of singly even order Magic squares of doubly even order See also MathWorld™ entry: Magic_square Odd Magic Squares (1728.org)
#Picat
Picat
import util.   go => foreach(N in [3,5,17]) M=magic_square(N), print_matrix(M), check(M), nl end, nl.   % % Not as nice as the J solution. % But I like the chaining of the functions. % magic_square(N) = MS => if N mod 2 = 0 then printf("N (%d) is not odd!\n", N), halt end, R = make_rotate_list(N), % the rotate indices MS = make_square(N).transpose().rotate_matrix(R).transpose().rotate_matrix(R).   % % make a square matrix of size N (containing the numbers 1..N*N) % make_square(N) = [[I*N+J : J in 1..N]: I in 0..N-1].   % % rotate list: % rotate_list(11) = [-5,-4,-3,-2,-1,0,1,2,3,4,5] % make_rotate_list(N) = [I - ceiling(N / 2) : I in 1..N].   % % rotate the matrix M according to rotate list R % rotate_matrix(M, R) = [rotate_n(Row,N) : {Row,N} in zip(M,R)].   % % Rotate the list L N steps (either positive or negative N) % rotate(1..10,3) -> [4,5,6,7,8,9,10,1,2,3] % rotate(1..10,-3) -> [8,9,10,1,2,3,4,5,6,7] % rotate_n(L,N) = Rot => Len = L.length, R = cond(N < 0, Len + N, N), Rot = [L[I] : I in (R+1..Len) ++ 1..R].   % % Check if M is a magic square % check(M) => N = M.length, Sum = N*(N*N+1) // 2, % The correct sum. println(sum=Sum), Rows = [sum(Row) : Row in M], Cols = [sum(Col) : Col in M.transpose()], Diag1 = sum([M[I,I] : I in 1..N]), Diag2 = sum([M[I,N-I+1] : I in 1..N]), All = Rows ++ Cols ++ [Diag1, Diag2], OK = true, foreach(X in All) if X != Sum then printf("%d != %d\n", X, Sum), OK := false end end, if OK then println(ok) else println(not_ok) end, nl.   % Print the matrix print_matrix(M) => N = M.len, printf("N=%d\n",N), Format = to_fstring("%%%dd",max(flatten(M)).to_string().length+1), foreach(Row in M) foreach(X in Row) printf(Format, X) end, nl end, nl.
http://rosettacode.org/wiki/Magic_squares_of_odd_order
Magic squares of odd order
A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers are usually (but not always) the first   N2   positive integers. A magic square whose rows and columns add up to a magic number but whose main diagonals do not, is known as a semimagic square. 8 1 6 3 5 7 4 9 2 Task For any odd   N,   generate a magic square with the integers   1 ──► N,   and show the results here. Optionally, show the magic number. You should demonstrate the generator by showing at least a magic square for   N = 5. Related tasks Magic squares of singly even order Magic squares of doubly even order See also MathWorld™ entry: Magic_square Odd Magic Squares (1728.org)
#PicoLisp
PicoLisp
(load "@lib/simul.l") (de magic (A) (let (Grid (grid A A T T) Sum (/ (* A (inc (** A 2))) 2)) (println 'N A 'Sum Sum) # cut one important edge (with (last (last Grid)) (con (: 0 1))) (with (get Grid (inc (/ A 2)) A) (for N (* A A) (=: V N) (setq This (if (with (setq @@ (north (east This))) (not (: V)) ) @@ (south This) ) ) ) ) # display (mapc '((L) (for This L (prin (align 4 (: V))) ) (prinl) ) Grid ) # clean (mapc '((L) (mapc zap L)) Grid) ) ) (magic 5) (prinl) (magic 7)
http://rosettacode.org/wiki/Matrix_multiplication
Matrix multiplication
Task Multiply two matrices together. They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
#Go
Go
package main   import ( "fmt"   "gonum.org/v1/gonum/mat" )   func main() { a := mat.NewDense(2, 4, []float64{ 1, 2, 3, 4, 5, 6, 7, 8, }) b := mat.NewDense(4, 3, []float64{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, }) var m mat.Dense m.Mul(a, b) fmt.Println(mat.Formatted(&m)) }
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#Pop11
Pop11
define A(k, x1, x2, x3, x4, x5); define B(); k - 1 -> k; A(k, B, x1, x2, x3, x4) enddefine; if k <= 0 then x4() + x5() else B() endif enddefine; define one(); 1 enddefine; define minus_one(); -1 enddefine; define zero(); 0 enddefine; A(10, one, minus_one, minus_one, one, zero) =>
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#Python
Python
#!/usr/bin/env python import sys sys.setrecursionlimit(1025)   def a(in_k, x1, x2, x3, x4, x5): k = [in_k] def b(): k[0] -= 1 return a(k[0], b, x1, x2, x3, x4) return x4() + x5() if k[0] <= 0 else b()   x = lambda i: lambda: i print(a(10, x(1), x(-1), x(-1), x(1), x(0)))  
http://rosettacode.org/wiki/Matrix_transposition
Matrix transposition
Transpose an arbitrarily sized rectangular Matrix.
#Groovy
Groovy
def matrix = [ [ 1, 2, 3, 4 ], [ 5, 6, 7, 8 ] ]   matrix.each { println it } println() def transpose = matrix.transpose()   transpose.each { println it }
http://rosettacode.org/wiki/Maze_generation
Maze generation
This page uses content from Wikipedia. The original article was at Maze generation algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) Task Generate and show a maze, using the simple Depth-first search algorithm. Start at a random cell. Mark the current cell as visited, and get a list of its neighbors. For each neighbor, starting with a randomly selected neighbor: If that neighbor hasn't been visited, remove the wall between this cell and that neighbor, and then recurse with that neighbor as the current cell. Related tasks Maze solving.
#PicoLisp
PicoLisp
(load "@lib/simul.l")   (de maze (DX DY) (let Maze (grid DX DY) (let Fld (get Maze (rand 1 DX) (rand 1 DY)) (recur (Fld) (for Dir (shuffle '((west . east) (east . west) (south . north) (north . south))) (with ((car Dir) Fld) (unless (or (: west) (: east) (: south) (: north)) (put Fld (car Dir) This) (put This (cdr Dir) Fld) (recurse This) ) ) ) ) ) (for (X . Col) Maze (for (Y . This) Col (set This (cons (cons (: west) (or (: east) (and (= Y 1) (= X DX)) ) ) (cons (: south) (or (: north) (and (= X 1) (= Y DY)) ) ) ) ) ) ) Maze ) )   (de display (Maze) (disp Maze 0 '((This) " ")) )
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#PureBasic
PureBasic
Structure RR a.f b.f EndStructure   Procedure.f MapRange(*a.RR, *b.RR, s) Protected.f a1, a2, b1, b2 a1=*a\a: a2=*a\b b1=*b\a: b2=*b\b ProcedureReturn b1 + ((s - a1) * (b2 - b1) / (a2 - a1)) EndProcedure     ;- Test the function If OpenConsole() Define.RR Range1, Range2 Range1\a=0: Range1\b=10 Range2\a=-1:Range2\b=0 ; For i=0 To 10 PrintN(RSet(Str(i),2)+" maps to "+StrF(MapRange(@Range1, @Range2, i),1)) Next EndIf
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#Python
Python
>>> def maprange( a, b, s): (a1, a2), (b1, b2) = a, b return b1 + ((s - a1) * (b2 - b1) / (a2 - a1))   >>> for s in range(11): print("%2g maps to %g" % (s, maprange( (0, 10), (-1, 0), s)))     0 maps to -1 1 maps to -0.9 2 maps to -0.8 3 maps to -0.7 4 maps to -0.6 5 maps to -0.5 6 maps to -0.4 7 maps to -0.3 8 maps to -0.2 9 maps to -0.1 10 maps to 0
http://rosettacode.org/wiki/MD5
MD5
Task Encode a string using an MD5 algorithm.   The algorithm can be found on   Wikipedia. Optionally, validate your implementation by running all of the test values in   IETF RFC (1321)   for MD5. Additionally,   RFC 1321   provides more precise information on the algorithm than the Wikipedia article. Warning:   MD5 has known weaknesses, including collisions and forged signatures.   Users may consider a stronger alternative when doing production-grade cryptography, such as SHA-256 (from the SHA-2 family), or the upcoming SHA-3. If the solution on this page is a library solution, see   MD5/Implementation   for an implementation from scratch.
#PARI.2FGP
PARI/GP
#include <pari/pari.h> #include <openssl/md5.h>   #define HEX(x) (((x) < 10)? (x)+'0': (x)-10+'a')   /* * PARI/GP func: MD5 hash * * gp code: install("plug_md5", "s", "MD5", "<library path>"); */ GEN plug_md5(char *text) { char md[MD5_DIGEST_LENGTH]; char hash[sizeof(md) * 2 + 1]; int i;   MD5((unsigned char*)text, strlen(text), (unsigned char*)md);   for (i = 0; i < sizeof(md); i++) { hash[i+i] = HEX((md[i] >> 4) & 0x0f); hash[i+i+1] = HEX(md[i] & 0x0f); }   hash[sizeof(md) * 2] = 0;   return strtoGENstr(hash); }
http://rosettacode.org/wiki/Mandelbrot_set
Mandelbrot set
Mandelbrot set You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw the Mandelbrot set. Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
#F.23
F#
open System.Drawing open System.Windows.Forms type Complex = { re : float; im : float } let cplus (x:Complex) (y:Complex) : Complex = { re = x.re + y.re; im = x.im + y.im } let cmult (x:Complex) (y:Complex) : Complex = { re = x.re * y.re - x.im * y.im; im = x.re * y.im + x.im * y.re; }   let norm (x:Complex) : float = x.re*x.re + x.im*x.im   type Mandel = class inherit Form static member xPixels = 500 static member yPixels = 500 val mutable bmp : Bitmap member x.mandelbrot xMin xMax yMin yMax maxIter = let rec mandelbrotIterator z c n = if (norm z) > 2.0 then false else match n with | 0 -> true | n -> let z' = cplus ( cmult z z ) c in mandelbrotIterator z' c (n-1) let dx = (xMax - xMin) / (float (Mandel.xPixels)) let dy = (yMax - yMin) / (float (Mandel.yPixels)) in for xi = 0 to Mandel.xPixels-1 do for yi = 0 to Mandel.yPixels-1 do let c = {re = xMin + (dx * float(xi) ) ; im = yMin + (dy * float(yi) )} in if (mandelbrotIterator {re=0.;im=0.;} c maxIter) then x.bmp.SetPixel(xi,yi,Color.Azure) else x.bmp.SetPixel(xi,yi,Color.Black) done done   member public x.generate () = x.mandelbrot (-1.5) 0.5 (-1.0) 1.0 200 ; x.Refresh()   new() as x = {bmp = new Bitmap(Mandel.xPixels , Mandel.yPixels)} then x.Text <- "Mandelbrot set" ; x.Width <- Mandel.xPixels ; x.Height <- Mandel.yPixels ; x.BackgroundImage <- x.bmp; x.generate(); x.Show(); end   let f = new Mandel() do Application.Run(f)
http://rosettacode.org/wiki/Magic_squares_of_odd_order
Magic squares of odd order
A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers are usually (but not always) the first   N2   positive integers. A magic square whose rows and columns add up to a magic number but whose main diagonals do not, is known as a semimagic square. 8 1 6 3 5 7 4 9 2 Task For any odd   N,   generate a magic square with the integers   1 ──► N,   and show the results here. Optionally, show the magic number. You should demonstrate the generator by showing at least a magic square for   N = 5. Related tasks Magic squares of singly even order Magic squares of doubly even order See also MathWorld™ entry: Magic_square Odd Magic Squares (1728.org)
#PL.2FI
PL/I
magic: procedure options (main); /* 18 April 2014 */ declare n fixed binary;   put skip list ('What is the order of the magic square?'); get list (n); if n < 3 | iand(n, 1) = 0 then do; put skip list ('The value is out of range'); stop; end; put skip list ('The order is ' || trim(n));   begin; declare m(n, n) fixed, (i, j, k) fixed binary;   on subrg snap put data (i, j, k); m = 0; i = 1; j = (n+1)/2;   do k = 1 to n*n; if m(i,j) = 0 then m(i,j) = k; else do; i = i + 2; j = j + 1; if i > n then i = mod(i,n); if j > n then j = 1; m(i,j) = k; end; i = i - 1; j = j - 1; if i < 1 then i = n; if j < 1 then j = n; end;   do i = 1 to n; put skip edit (m(i, *)) (f(4)); end;   put skip list ('The magic number is' || sum(m(1,*))); end; end magic;
http://rosettacode.org/wiki/Matrix_multiplication
Matrix multiplication
Task Multiply two matrices together. They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
#Groovy
Groovy
def assertConformable = { a, b -> assert a instanceof List assert b instanceof List assert a.every { it instanceof List && it.size() == b.size() } assert b.every { it instanceof List && it.size() == b[0].size() } }   def matmulWOIL = { a, b -> assertConformable(a, b)   def bt = b.transpose() a.collect { ai -> bt.collect { btj -> [ai, btj].transpose().collect { it[0] * it[1] }.sum() } } }
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#R
R
n <- function(x) function()x   A <- function(k, x1, x2, x3, x4, x5) { B <- function() A(k <<- k-1, B, x1, x2, x3, x4) if (k <= 0) x4() + x5() else B() }   A(10, n(1), n(-1), n(-1), n(1), n(0))
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#Racket
Racket
#lang racket   (define (A k x1 x2 x3 x4 x5) (define (B) (set! k (- k 1)) (A k B x1 x2 x3 x4)) (if (<= k 0) (+ (x4) (x5)) (B)))   (A 10 (lambda () 1) (lambda () -1) (lambda () -1) (lambda () 1) (lambda () 0))
http://rosettacode.org/wiki/Matrix_transposition
Matrix transposition
Transpose an arbitrarily sized rectangular Matrix.
#Haskell
Haskell
*Main> transpose [[1,2],[3,4],[5,6]] [[1,3,5],[2,4,6]]
http://rosettacode.org/wiki/Maze_generation
Maze generation
This page uses content from Wikipedia. The original article was at Maze generation algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) Task Generate and show a maze, using the simple Depth-first search algorithm. Start at a random cell. Mark the current cell as visited, and get a list of its neighbors. For each neighbor, starting with a randomly selected neighbor: If that neighbor hasn't been visited, remove the wall between this cell and that neighbor, and then recurse with that neighbor as the current cell. Related tasks Maze solving.
#PL.2FI
PL/I
*process source attributes xref or(!); mgg: Proc Options(main); /* REXX *************************************************************** * 04.09.2013 Walter Pachl translated from REXX version 3 **********************************************************************/ Dcl (MIN,MOD,RANDOM,REPEAT,SUBSTR) Builtin; Dcl SYSIN STREAM INPUT; Dcl print Print; Dcl imax Bin Fixed(31) init(10); Dcl jmax Bin Fixed(31) init(15); Dcl seed Bin Fixed(31) init(4711); Get File(sysin) Data(imax,jmax,seed); Dcl ii Bin Fixed(31); Dcl jj Bin Fixed(31); Dcl id Bin Fixed(31); Dcl jd Bin Fixed(31); id=2*imax+1; /* vertical dimension of a.i.j */ jd=2*jmax+1; /* horizontal dimension of a.i.j */ Dcl c Char(2000) Var; c=repeat('123456789'!!'abcdefghijklmnopqrstuvwxyz'!! 'ABCDEFGHIJKLMNOPQRSTUVWXYZ',20); Dcl x Bin Float(53); x=random(seed); Dcl ps Bin Fixed(31) Init(1); /* first position */ Dcl na Bin Fixed(31) Init(1); /* number of points used */ Dcl si Bin Fixed(31); /* loop to compute paths */ Begin; Dcl a(id,jd) Bin Fixed(15); Dcl p(imax,jmax) Char(1); Dcl 1 pl(imax*jmax), 2 ic Bin Fixed(15), 2 jc Bin Fixed(15); Dcl 1 np(imax*jmax), 2 ic Bin Fixed(15), 2 jc Bin Fixed(15); Dcl 1 pos(imax*jmax), 2 ic Bin Fixed(15), 2 jc Bin Fixed(15); Dcl npl Bin Fixed(31) Init(0); a=1; /* mark all borders present */ p='.'; /* Initialize all grid points */ ii=rnd(imax); /* find a start position */ jj=rnd(jmax); Do si=1 To 1000; /* Do Forever - see Leave */ Call path(ii,jj); /* compute a path starting at ii/jj */ If na=imax*jmax Then /* all points used */ Leave; /* we are done */ Call select_next(ii,jj); /* get a new start from a path*/ End; Call show; Return;   path: Procedure(ii,jj); /********************************************************************** * compute a path starting from point (ii,jj) **********************************************************************/ Dcl ii Bin Fixed(31); Dcl jj Bin Fixed(31); Dcl nb Bin Fixed(31); Dcl ch Bin Fixed(31); Dcl pp Bin Fixed(31); p(ii,jj)='1'; pos.ic(ps)=ii; pos.jc(ps)=jj; Do pp=1 to 50; /* compute a path of maximum length 50*/ nb=neighbors(ii,jj); /* number of free neighbors */ Select; When(nb=1) /* just one */ Call advance((1),ii,jj); /* go for it */ When(nb>0) Do; /* more Than 1 */ ch=rnd(nb); /* choose one possibility */ Call advance(ch,ii,jj); /* and go for that */ End; Otherwise /* none available */ Leave; End; End; End;   neighbors: Procedure(i,j) Returns(Bin Fixed(31)); /********************************************************************** * count the number of free neighbors of point (i,j) **********************************************************************/ Dcl i Bin Fixed(31); Dcl j Bin Fixed(31); Dcl in Bin Fixed(31); Dcl jn Bin Fixed(31); Dcl nb Bin Fixed(31) Init(0); in=i-1; If in>0 Then Call check(in,j,nb); in=i+1; If in<=imax Then Call check(in,j,nb); jn=j-1; If jn>0 Then Call check(i,jn,nb); jn=j+1; If jn<=jmax Then Call check(i,jn,nb); Return(nb); End;   check: Procedure(i,j,n); /********************************************************************** * check if point (i,j) is free and note it as possible successor **********************************************************************/ Dcl i Bin Fixed(31); Dcl j Bin Fixed(31); Dcl n Bin Fixed(31); If p(i,j)='.' Then Do; /* point is free */ n+=1; /* number of free neighbors */ np.ic(n)=i; /* note it as possible choice */ np.jc(n)=j; End; End;   advance: Procedure(ch,ii,jj); /********************************************************************** * move to the next point of the current path **********************************************************************/ Dcl ch Bin Fixed(31); Dcl ii Bin Fixed(31); Dcl jj Bin Fixed(31); Dcl ai Bin Fixed(31); Dcl aj Bin Fixed(31); Dcl pii Bin Fixed(31) Init((ii)); Dcl pjj Bin Fixed(31) Init((jj)); Dcl z Bin Fixed(31); ii=np.ic(ch); jj=np.jc(ch); ps+=1; /* position number */ pos.ic(ps)=ii; /* note its coordinates */ pos.jc(ps)=jj; p(ii,jj)=substr(c,ps,1); /* mark the point as used */ ai=pii+ii; /* vertical border position */ aj=pjj+jj; /* horizontal border position */ a(ai,aj)=0; /* tear the border down */ na+=1; /* number of used positions */ z=npl+1; /* add the point to the list */ pl.ic(z)=ii; /* of follow-up start pos. */ pl.jc(z)=jj; npl=z; End;   show: Procedure; /********************************************************************* * Show the resulting maze *********************************************************************/ Dcl i Bin Fixed(31); Dcl j Bin Fixed(31); Dcl ol Char(300) Var; Put File(print) Edit('mgg',imax,jmax,seed)(Skip,a,3(f(4))); Put File(print) Skip Data(na); Do i=1 To id; ol=''; Do j=1 To jd; If mod(i,2)=1 Then Do; /* odd lines */ If a(i,j)=1 Then Do; /* border to be drawn */ If mod(j,2)=0 Then ol=ol!!'---'; /* draw the border */ Else ol=ol!!'+'; End; Else Do; /* border was torn down */ If mod(j,2)=0 Then ol=ol!!' '; /* blanks instead of border */ Else ol=ol!!'+'; End; End; Else Do; /* even line */ If a(i,j)=1 Then Do; If mod(j,2)=0 Then /* even column */ ol=ol!!' '; /* moving space */ Else /* odd column */ ol=ol!!'!'; /* draw the border */ End; Else /* border was torn down */ ol=ol!!' '; /* blank instead of border */ End; End; Select; When(i=6) substr(ol,11,1)='A'; When(i=8) substr(ol, 3,1)='B'; Otherwise; End; Put File(print) Edit(ol,i)(Skip,a,f(3)); End; End;   select_next: Procedure(is,js); /********************************************************************** * look for a point to start the nnext path **********************************************************************/ Dcl is Bin Fixed(31); Dcl js Bin Fixed(31); Dcl n Bin Fixed(31); Dcl nb Bin Fixed(31); Dcl s Bin Fixed(31); Do Until(nb>0); /* loop until one is found */ n=npl; /* number of points recorded */ s=rnd(n); /* pick a random index */ is=pl.ic(s); /* its coordinates */ js=pl.jc(s); nb=neighbors(is,js); /* count free neighbors */ If nb=0 Then Do; /* if there is none */ pl.ic(s)=pl.ic(n); /* remove this point */ pl.jc(s)=pl.jc(n); npl-=1; End; End; End;   rnd: Proc(n) Returns(Bin Fixed(31)); /********************************************************************* * return a pseudo-random integer between 1 and n *********************************************************************/ dcl (r,n) Bin Fixed(31); r=min(random()*n+1,n); Return(r); End;   End; End;
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#R
R
tRange <- function(aRange, bRange, s) { #Guard clauses. We could write some proper error messages, but this is all we really need. stopifnot(length(aRange) == 2, length(bRange) == 2, is.numeric(aRange), is.numeric(bRange), is.numeric(s), s >= aRange[1], s <= aRange[2]) bRange[1] + ((s - aRange[1]) * (bRange[2] - bRange[1])) / (aRange[2] - aRange[1]) } data.frame(s = 0:10, t = sapply(0:10, tRange, aRange = c(0, 10), bRange = c(-1, 0)))
http://rosettacode.org/wiki/MD5
MD5
Task Encode a string using an MD5 algorithm.   The algorithm can be found on   Wikipedia. Optionally, validate your implementation by running all of the test values in   IETF RFC (1321)   for MD5. Additionally,   RFC 1321   provides more precise information on the algorithm than the Wikipedia article. Warning:   MD5 has known weaknesses, including collisions and forged signatures.   Users may consider a stronger alternative when doing production-grade cryptography, such as SHA-256 (from the SHA-2 family), or the upcoming SHA-3. If the solution on this page is a library solution, see   MD5/Implementation   for an implementation from scratch.
#Pascal
Pascal
  program GetMd5;   uses md5;   var strEncrypted : string;   begin strEncrypted := md5Print(md5String('The quick brown fox jumped over the lazy dog''s back')); writeln(strEncrypted); end.  
http://rosettacode.org/wiki/Mandelbrot_set
Mandelbrot set
Mandelbrot set You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw the Mandelbrot set. Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
#Factor
Factor
  ! with ("::") or without (":") generalizations: ! : [a..b] ( steps a b -- a..b ) 2dup swap - 4 nrot 1 - / <range> ; :: [a..b] ( steps a b -- a..b ) a b b a - steps 1 - / <range> ;   : >char ( n -- c ) dup -1 = [ drop 32 ] [ 26 mod CHAR: a + ] if ;   ! iterates z' = z^2 + c, Factor does complex numbers! : iter ( c z -- z' ) dup * + ;   : unbound ( c -- ? ) absq 4 > ;   :: mz ( c max i z -- n ) { { [ i max >= ] [ -1 ] } { [ z unbound ] [ i ] } [ c max i 1 + c z iter mz ] } cond ;   : mandelzahl ( c max -- n ) 0 0 mz ;   :: mandel ( w h max -- ) h -1. 1. [a..b] ! range over y [ w -2. 1. [a..b] ! range over x [ dupd swap rect> max mandelzahl >char ] map >string print drop ! old y ] each  ;   70 25 1000 mandel    
http://rosettacode.org/wiki/Magic_squares_of_odd_order
Magic squares of odd order
A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers are usually (but not always) the first   N2   positive integers. A magic square whose rows and columns add up to a magic number but whose main diagonals do not, is known as a semimagic square. 8 1 6 3 5 7 4 9 2 Task For any odd   N,   generate a magic square with the integers   1 ──► N,   and show the results here. Optionally, show the magic number. You should demonstrate the generator by showing at least a magic square for   N = 5. Related tasks Magic squares of singly even order Magic squares of doubly even order See also MathWorld™ entry: Magic_square Odd Magic Squares (1728.org)
#PureBasic
PureBasic
#N=9 Define.i i,j   If OpenConsole("Magic squares") PrintN("The square order is: "+Str(#N)) For i=1 To #N For j=1 To #N Print(RSet(Str((i*2-j+#N-1) % #N*#N + (i*2+j-2) % #N+1),5)) Next PrintN("") Next PrintN("The magic number is: "+Str(#N*(#N*#N+1)/2)) EndIf Input()
http://rosettacode.org/wiki/Matrix_multiplication
Matrix multiplication
Task Multiply two matrices together. They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
#Haskell
Haskell
import Data.List   mmult :: Num a => [[a]] -> [[a]] -> [[a]] mmult a b = [ [ sum $ zipWith (*) ar bc | bc <- (transpose b) ] | ar <- a ]   -- Example use: test = [[1, 2], [3, 4]] `mmult` [[-3, -8, 3], [-2, 1, 4]]
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#Raku
Raku
sub A($k is copy, &x1, &x2, &x3, &x4, &x5) { $k <= 0 ?? x4() + x5() !! (my &B = { A(--$k, &B, &x1, &x2, &x3, &x4) })(); };   say A(10, {1}, {-1}, {-1}, {1}, {0});
http://rosettacode.org/wiki/Matrix_transposition
Matrix transposition
Transpose an arbitrarily sized rectangular Matrix.
#Haxe
Haxe
class Matrix { static function main() { var m = [ [1, 1, 1, 1], [2, 4, 8, 16], [3, 9, 27, 81], [4, 16, 64, 256], [5, 25, 125, 625] ]; var t = [ for (i in 0...m[0].length) [ for (j in 0...m.length) 0 ] ]; for(i in 0...m.length) for(j in 0...m[0].length) t[j][i] = m[i][j];   for(aa in [m, t]) for(a in aa) Sys.println(a); } }
http://rosettacode.org/wiki/Maze_generation
Maze generation
This page uses content from Wikipedia. The original article was at Maze generation algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) Task Generate and show a maze, using the simple Depth-first search algorithm. Start at a random cell. Mark the current cell as visited, and get a list of its neighbors. For each neighbor, starting with a randomly selected neighbor: If that neighbor hasn't been visited, remove the wall between this cell and that neighbor, and then recurse with that neighbor as the current cell. Related tasks Maze solving.
#Processing
Processing
int g_size = 10; color background_color = color (80, 80, 220); color runner = color (255, 50, 50); color visited_color = color(220, 240, 240); color done_color = color (100, 160, 250); int c_size;   Cell[][] cell; ArrayList<Cell> done = new ArrayList<Cell>(); ArrayList<Cell> visit = new ArrayList<Cell>(); Cell run_cell;   void setup() { size(600, 600); frameRate(20); smooth(4); strokeCap(ROUND); c_size = max(width/g_size, height/g_size); cell = new Cell[g_size][g_size]; for (int i = 0; i < g_size; i++) { for (int j = 0; j < g_size; j++) { cell[i][j] = new Cell(i, j); } } for (int i = 0; i < g_size; i++) { for (int j = 0; j < g_size; j++) { cell[i][j].add_neighbor(); } } run_cell = cell[0][0]; visit.add(run_cell); }   void draw() { background(background_color); for (int i = 0; i < g_size; i++) { for (int j = 0; j < g_size; j++) { cell[i][j].draw_cell(); cell[i][j].draw_wall(); } } if (visit.size() < g_size*g_size) { if (run_cell.check_sides()) { Cell chosen = run_cell.pick_neighbor(); done.add(run_cell); run_cell.stacked = true; if (chosen.i - run_cell.i == 1) { run_cell.wall[1] = false; chosen.wall[3] = false; } else if (chosen.i - run_cell.i == -1) { run_cell.wall[3] = false; chosen.wall[1] = false; } else if (chosen.j - run_cell.j == 1) { run_cell.wall[2] = false; chosen.wall[0] = false; } else { run_cell.wall[0] = false; chosen.wall[2] = false; } run_cell.current = false; run_cell = chosen; run_cell.current = true; run_cell.visited = true; } else if (done.size()>0) { run_cell.current = false; run_cell = done.remove(done.size()-1); run_cell.stacked = false; run_cell.current = true; } } }   class Cell { ArrayList<Cell> neighbor; boolean visited, stacked, current; boolean[] wall; int i, j;   Cell(int _i, int _j) { i = _i; j = _j; wall = new boolean[]{true,true,true,true}; }   Cell pick_neighbor() { ArrayList<Cell> unvisited = new ArrayList<Cell>(); for(int i = 0; i < neighbor.size(); i++){ Cell nb = neighbor.get(i); if(nb.visited == false) unvisited.add(nb); } return unvisited.get(floor(random(unvisited.size()))); }   void add_neighbor() { neighbor = new ArrayList<Cell>(); if(i>0){neighbor.add(cell[i-1][j]);} if(i<g_size-1){neighbor.add(cell[i+1][j]);} if(j>0){neighbor.add(cell[i][j-1]);} if(j<g_size-1){neighbor.add(cell[i][j+1]);} }   boolean check_sides() { for(int i = 0; i < neighbor.size(); i++){ Cell nb = neighbor.get(i); if(!nb.visited) return true; } return false; }   void draw_cell() { noStroke(); noFill(); if(current) fill(runner); else if(stacked) fill(done_color); else if(visited) fill(visited_color); rect(j*c_size,i*c_size,c_size,c_size); }   void draw_wall() { stroke(0); strokeWeight(5); if(wall[0]) line(j*c_size, i*c_size, j*c_size, (i+1)* c_size); if(wall[1]) line(j*c_size, (i+1)*c_size, (j+1)*c_size, (i+1)*c_size); if(wall[2]) line((j+1)*c_size, (i+1)*c_size, (j+1)*c_size, i*c_size); if(wall[3]) line((j+1)*c_size, i*c_size, j*c_size, i*c_size); } }
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#Racket
Racket
  #lang racket   (define (make-range-map a1 a2 b1 b2)  ;; returns a mapping function, doing computing the differences in  ;; advance so it's fast (let ([a (- a2 a1)] [b (- b2 b1)]) (λ(s) (exact->inexact (+ b1 (/ (* (- s a1) b) a))))))   (define map (make-range-map 0 10 -1 0)) (for ([i (in-range 0 11)]) (printf "~a --> ~a\n" i (map i)))  
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#Raku
Raku
sub getmapper(Range $a, Range $b) { my ($a1, $a2) = $a.bounds; my ($b1, $b2) = $b.bounds; return -> $s { $b1 + (($s-$a1) * ($b2-$b1) / ($a2-$a1)) } }   my &mapper = getmapper(0 .. 10, -1 .. 0); for ^11 -> $x {say "$x maps to &mapper($x)"}
http://rosettacode.org/wiki/MD5
MD5
Task Encode a string using an MD5 algorithm.   The algorithm can be found on   Wikipedia. Optionally, validate your implementation by running all of the test values in   IETF RFC (1321)   for MD5. Additionally,   RFC 1321   provides more precise information on the algorithm than the Wikipedia article. Warning:   MD5 has known weaknesses, including collisions and forged signatures.   Users may consider a stronger alternative when doing production-grade cryptography, such as SHA-256 (from the SHA-2 family), or the upcoming SHA-3. If the solution on this page is a library solution, see   MD5/Implementation   for an implementation from scratch.
#Perl
Perl
use Digest::MD5 qw(md5_hex);   print md5_hex("The quick brown fox jumped over the lazy dog's back"), "\n";
http://rosettacode.org/wiki/Mandelbrot_set
Mandelbrot set
Mandelbrot set You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw the Mandelbrot set. Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
#Fennel
Fennel
  #!/usr/bin/env fennel   (fn mandelzahl [cr ci max i tr ti tr2 ti2] "Calculates the Mandelbrot escape number of a complex point c" (if (>= i max) -1 (>= (+ tr2 ti2) 4) i (let [(tr ti) (values (+ (- tr2 ti2) cr) (+ (* tr ti 2) ci))] (mandelzahl cr ci max (+ i 1) tr ti (* tr tr) (* ti ti)))))   (fn mandel [w h max] "Entry point, generate a 'graphical' representation of the Mandelbrot set" (for [y -1.0 1.0 (/ 2.0 h)] (var line {}) (for [x -2.0 1.0 (/ 3.0 w)] (let [mz (mandelzahl x y max 0 0 0 0 0)] (tset line (+ (length line) 1) (or (and (< mz 0) " ") (string.char (+ (string.byte :a) (% mz 26))))))) (print (table.concat line))))   (fn arg-def [pos default] "A helper fn to extract command line parameter with defaults" (or (tonumber (and arg (. arg pos))) default))   (let [width (arg-def 1 140) height (arg-def 2 50) max (arg-def 3 1e5)] (mandel width height max))  
http://rosettacode.org/wiki/Magic_squares_of_odd_order
Magic squares of odd order
A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers are usually (but not always) the first   N2   positive integers. A magic square whose rows and columns add up to a magic number but whose main diagonals do not, is known as a semimagic square. 8 1 6 3 5 7 4 9 2 Task For any odd   N,   generate a magic square with the integers   1 ──► N,   and show the results here. Optionally, show the magic number. You should demonstrate the generator by showing at least a magic square for   N = 5. Related tasks Magic squares of singly even order Magic squares of doubly even order See also MathWorld™ entry: Magic_square Odd Magic Squares (1728.org)
#Python
Python
>>> def magic(n): for row in range(1, n + 1): print(' '.join('%*i' % (len(str(n**2)), cell) for cell in (n * ((row + col - 1 + n // 2) % n) + ((row + 2 * col - 2) % n) + 1 for col in range(1, n + 1)))) print('\nAll sum to magic number %i' % ((n * n + 1) * n // 2))     >>> for n in (5, 3, 7): print('\nOrder %i\n=======' % n) magic(n)       Order 5 ======= 17 24 1 8 15 23 5 7 14 16 4 6 13 20 22 10 12 19 21 3 11 18 25 2 9   All sum to magic number 65   Order 3 ======= 8 1 6 3 5 7 4 9 2   All sum to magic number 15   Order 7 ======= 30 39 48 1 10 19 28 38 47 7 9 18 27 29 46 6 8 17 26 35 37 5 14 16 25 34 36 45 13 15 24 33 42 44 4 21 23 32 41 43 3 12 22 31 40 49 2 11 20   All sum to magic number 175 >>>
http://rosettacode.org/wiki/Matrix_multiplication
Matrix multiplication
Task Multiply two matrices together. They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
#HicEst
HicEst
REAL :: m=4, n=2, p=3, a(m,n), b(n,p), res(m,p)   a = $ ! initialize to 1, 2, ..., m*n b = $ ! initialize to 1, 2, ..., n*p   res = 0 DO i = 1, m DO j = 1, p DO k = 1, n res(i,j) = res(i,j) + a(i,k) * b(k,j) ENDDO ENDDO ENDDO   DLG(DefWidth=4, Text=a, Text=b,Y=0, Text=res,Y=0)
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#REXX
REXX
/*REXX program performs the "man or boy" test as far as possible for N. */ do n=0 /*increment N from zero forever. */ say 'n='n a(N,x1,x2,x3,x4,x5) /*display the result to the terminal. */ end /*n*/ /* [↑] do until something breaks. */ exit /*stick a fork in it, we're all done. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ a: procedure; parse arg k, x1, x2, x3, x4, x5 if k<=0 then return f(x4) + f(x5) else return f(b) /*──────────────────────────────────────────────────────────────────────────────────────*/ b: k=k-1; return a(k, b, x1, x2, x3, x4) f: interpret 'v=' arg(1)"()"; return v x1: procedure; return 1 x2: procedure; return -1 x3: procedure; return -1 x4: procedure; return 1 x5: procedure; return 0
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#Ruby
Ruby
def a(k, x1, x2, x3, x4, x5) b = lambda { k -= 1; a(k, b, x1, x2, x3, x4) } k <= 0 ? x4[] + x5[] : b[] end   puts a(10, lambda {1}, lambda {-1}, lambda {-1}, lambda {1}, lambda {0})
http://rosettacode.org/wiki/Matrix_transposition
Matrix transposition
Transpose an arbitrarily sized rectangular Matrix.
#HicEst
HicEst
REAL :: mtx(2, 4)   mtx = 1.1 * $ WRITE() mtx   SOLVE(Matrix=mtx, Transpose=mtx) WRITE() mtx
http://rosettacode.org/wiki/Maze_generation
Maze generation
This page uses content from Wikipedia. The original article was at Maze generation algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) Task Generate and show a maze, using the simple Depth-first search algorithm. Start at a random cell. Mark the current cell as visited, and get a list of its neighbors. For each neighbor, starting with a randomly selected neighbor: If that neighbor hasn't been visited, remove the wall between this cell and that neighbor, and then recurse with that neighbor as the current cell. Related tasks Maze solving.
#Prolog
Prolog
:- dynamic cell/2.   maze(Lig,Col) :- retractall(cell(_,_)),   new(D, window('Maze')),   % creation of the grid forall(between(0,Lig, I), (XL is 50, YL is I * 30 + 50, XR is Col * 30 + 50, new(L, line(XL, YL, XR, YL)), send(D, display, L))),   forall(between(0,Col, I), (XT is 50 + I * 30, YT is 50, YB is Lig * 30 + 50, new(L, line(XT, YT, XT, YB)), send(D, display, L))),   SX is Col * 30 + 100, SY is Lig * 30 + 100, send(D, size, new(_, size(SX, SY))),   % choosing a first cell L0 is random(Lig), C0 is random(Col), assert(cell(L0, C0)), \+search(D, Lig, Col, L0, C0), send(D, open).   search(D, Lig, Col, L, C) :- Dir is random(4), nextcell(Dir, Lig, Col, L, C, L1, C1), assert(cell(L1,C1)), assert(cur(L1,C1)), erase_line(D, L, C, L1, C1), search(D, Lig, Col, L1, C1).   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% erase_line(D, L, C, L, C1) :- ( C < C1 -> C2 = C1; C2 = C), XT is C2 * 30 + 50, YT is L * 30 + 51, YR is (L+1) * 30 + 50, new(Line, line(XT, YT, XT, YR)), send(Line, colour, white), send(D, display, Line).   erase_line(D, L, C, L1, C) :- XT is 51 + C * 30, XR is 50 + (C + 1) * 30, ( L < L1 -> L2 is L1; L2 is L), YT is L2 * 30 + 50, new(Line, line(XT, YT, XR, YT)), send(Line, colour, white), send(D, display, Line).   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% nextcell(Dir, Lig, Col, L, C, L1, C1) :- next(Dir, Lig, Col, L, C, L1, C1); ( Dir1 is (Dir+3) mod 4, next(Dir1, Lig, Col, L, C, L1, C1)); ( Dir2 is (Dir+1) mod 4, next(Dir2, Lig, Col, L, C, L1, C1)); ( Dir3 is (Dir+2) mod 4, next(Dir3, Lig, Col, L, C, L1, C1)).   % 0 => northward next(0, _Lig, _Col, L, C, L1, C) :- L > 0, L1 is L - 1, \+cell(L1, C).   % 1 => rightward next(1, _Lig, Col, L, C, L, C1) :- C < Col - 1, C1 is C + 1, \+cell(L, C1).   % 2 => southward next(2, Lig, _Col, L, C, L1, C) :- L < Lig - 1, L1 is L + 1, \+cell(L1, C).   % 3 => leftward next(2, _Lig, _Col, L, C, L, C1) :- C > 0, C1 is C - 1, \+cell(L, C1).    
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#ReScript
ReScript
let map_range = ((a1, a2), (b1, b2), s) => { b1 +. ((s -. a1) *. (b2 -. b1) /. (a2 -. a1)) }   Js.log("Mapping [0,10] to [-1,0] at intervals of 1:")   for i in 0 to 10 { Js.log("f(" ++ Js.String.make(i) ++ ") = " ++ Js.String.make(map_range((0.0, 10.0), (-1.0, 0.0), float(i)))) }
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#REXX
REXX
/*REXX program maps and displays a range of numbers from one range to another range.*/ rangeA = 0 10 /*or: rangeA = ' 0 10 ' */ rangeB = -1 0 /*or: rangeB = " -1 0 " */ parse var rangeA L H inc= 1 do j=L to H by inc * (1 - 2 * sign(H<L) ) /*BY: either +inc or -inc */ say right(j, 9) ' maps to ' mapR(rangeA, rangeB, j) end /*j*/ exit /*stick a fork in it, we're done.*/ /*──────────────────────────────────────────────────────────────────────────────────────*/ mapR: procedure; parse arg a1 a2,b1 b2,s;$=b1+(s-a1)*(b2-b1)/(a2-a1);return left('',$>=0)$
http://rosettacode.org/wiki/MD5
MD5
Task Encode a string using an MD5 algorithm.   The algorithm can be found on   Wikipedia. Optionally, validate your implementation by running all of the test values in   IETF RFC (1321)   for MD5. Additionally,   RFC 1321   provides more precise information on the algorithm than the Wikipedia article. Warning:   MD5 has known weaknesses, including collisions and forged signatures.   Users may consider a stronger alternative when doing production-grade cryptography, such as SHA-256 (from the SHA-2 family), or the upcoming SHA-3. If the solution on this page is a library solution, see   MD5/Implementation   for an implementation from scratch.
#Phix
Phix
$string = "The quick brown fox jumped over the lazy dog's back"; echo md5( $string );
http://rosettacode.org/wiki/Mandelbrot_set
Mandelbrot set
Mandelbrot set You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw the Mandelbrot set. Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
#FOCAL
FOCAL
1.1 S I1=-1.2; S I2=1.2; S R1=-2; S R2=.5 1.2 S MIT=30 1.3 F Y=1,24; D 2 1.4 Q   2.1 T ! 2.2 F X=1,70; D 3   3.1 S R=X*(R2-R1)/70+R1 3.2 S I=Y*(I2-I1)/24+I1 3.3 S C1=R; S C2=I 3.4 F T=1,MIT; D 4   4.1 S C3=C1 4.2 S C1=C1*C1 - C2*C2 4.3 S C2=C3*C2 + C2*C3 4.4 S C1=C1+R 4.5 S C2=C2+I 4.6 I (-FABS(C1)+2)5.1 4.7 I (-FABS(C2)+2)5.1 4.8 I (MIT-T-1)6.1   5.1 S T=MIT; T "*"; R   6.1 T " "; R
http://rosettacode.org/wiki/Magic_squares_of_odd_order
Magic squares of odd order
A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers are usually (but not always) the first   N2   positive integers. A magic square whose rows and columns add up to a magic number but whose main diagonals do not, is known as a semimagic square. 8 1 6 3 5 7 4 9 2 Task For any odd   N,   generate a magic square with the integers   1 ──► N,   and show the results here. Optionally, show the magic number. You should demonstrate the generator by showing at least a magic square for   N = 5. Related tasks Magic squares of singly even order Magic squares of doubly even order See also MathWorld™ entry: Magic_square Odd Magic Squares (1728.org)
#QB64
QB64
_Title "Magic Squares of Odd Order" '$Dynamic DefLng A-Z Dim Shared As Long m(1, 1)   Call magicSquare(5) Call magicSquare(15)   Sleep System   Sub magicSquare (n As Integer) Dim As Integer inc, count, row, col   If (n < 3) Or (n And 1) <> 1 Then n = 3 ReDim m(n, n) inc = 1 count = 1 row = 1 col = (n + 1) / 2 While count <= n * n m(row, col) = count count = count + 1 If inc < n Then inc = inc + 1 row = row - 1 col = col + 1 If row <> 0 Then If col > n Then col = 1 Else row = n End If Else inc = 1 row = row + 1 End If Wend Call printSquare(n) End Sub   Sub printSquare (n As Integer) Dim As Integer row, col 'Arbitrary limit ensures a fit within console window 'Can be any size that fits within your computers memory limits If n < 21 Then Print "Order "; n; " Magic Square constant is "; Str$(Int((n * n + 1) / 2 * n)) For row = 1 To n For col = 1 To n Print Using "####"; m(row, col); Next col Print ' Print Next row End If End Sub
http://rosettacode.org/wiki/Magic_squares_of_odd_order
Magic squares of odd order
A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers are usually (but not always) the first   N2   positive integers. A magic square whose rows and columns add up to a magic number but whose main diagonals do not, is known as a semimagic square. 8 1 6 3 5 7 4 9 2 Task For any odd   N,   generate a magic square with the integers   1 ──► N,   and show the results here. Optionally, show the magic number. You should demonstrate the generator by showing at least a magic square for   N = 5. Related tasks Magic squares of singly even order Magic squares of doubly even order See also MathWorld™ entry: Magic_square Odd Magic Squares (1728.org)
#R
R
> magic(5) [,1] [,2] [,3] [,4] [,5] [1,] 17 24 1 8 15 [2,] 23 5 7 14 16 [3,] 4 6 13 20 22 [4,] 10 12 19 21 3 [5,] 11 18 25 2 9
http://rosettacode.org/wiki/Matrix_multiplication
Matrix multiplication
Task Multiply two matrices together. They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
#Icon_and_Unicon
Icon and Unicon
  link matrix   procedure main () m1 := [[1,2,3], [4,5,6]] m2 := [[1,2],[3,4],[5,6]] m3 := mult_matrix (m1, m2) write ("Multiply:") write_matrix ("", m1) # first argument is filename, or "" for stdout write ("by:") write_matrix ("", m2) write ("Result: ") write_matrix ("", m3) end  
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#Rust
Rust
use std::cell::Cell;   trait Arg { fn run(&self) -> i32; }   impl Arg for i32 { fn run(&self) -> i32 { *self } }   struct B<'a> { k: &'a Cell<i32>, x1: &'a Arg, x2: &'a Arg, x3: &'a Arg, x4: &'a Arg, }   impl<'a> Arg for B<'a> { fn run(&self) -> i32 { self.k.set(self.k.get() - 1); a(self.k.get(), self, self.x1, self.x2, self.x3, self.x4) } }   fn a(k: i32, x1: &Arg, x2: &Arg, x3: &Arg, x4: &Arg, x5: &Arg) -> i32 { if k <= 0 { x4.run() + x5.run() } else { B{ k: &Cell::new(k), x1, x2, x3, x4 }.run() } }   pub fn main() { println!("{}", a(10, &1, &-1, &-1, &1, &0)); }
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#Scala
Scala
def A(in_k: Int, x1: =>Int, x2: =>Int, x3: =>Int, x4: =>Int, x5: =>Int): Int = { var k = in_k def B: Int = { k = k-1 A(k, B, x1, x2, x3, x4) } if (k<=0) x4+x5 else B } println(A(10, 1, -1, -1, 1, 0))
http://rosettacode.org/wiki/Matrix_transposition
Matrix transposition
Transpose an arbitrarily sized rectangular Matrix.
#Hope
Hope
uses lists; dec transpose : list (list alpha) -> list (list alpha); --- transpose ([]::_) <= []; --- transpose n <= map head n :: transpose (map tail n);
http://rosettacode.org/wiki/Maze_generation
Maze generation
This page uses content from Wikipedia. The original article was at Maze generation algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) Task Generate and show a maze, using the simple Depth-first search algorithm. Start at a random cell. Mark the current cell as visited, and get a list of its neighbors. For each neighbor, starting with a randomly selected neighbor: If that neighbor hasn't been visited, remove the wall between this cell and that neighbor, and then recurse with that neighbor as the current cell. Related tasks Maze solving.
#PureBasic
PureBasic
Enumeration ;indexes for types of offsets from maze coordinates (x,y) #visited ;used to index visited(x,y) in a given direction from current maze cell #maze ;used to index maze() in a given direction from current maze cell #wall ;used to index walls in maze() in a given direction from current maze cell #numOffsets = #wall ;direction indexes #dir_ID = 0 ;identity value, produces no changes #firstDir #dir_N = #firstDir #dir_E #dir_S #dir_W #numDirs = #dir_W EndEnumeration   DataSection ;maze(x,y) offsets for visited, maze, & walls for each direction Data.i 1, 1, 0, 0, 0, 0 ;ID Data.i 1, 0, 0, -1, 0, 0 ;N Data.i 2, 1, 1, 0, 1, 0 ;E Data.i 1, 2, 0, 1, 0, 1 ;S Data.i 0, 1, -1, 0, 0, 0 ;W Data.i %00, %01, %10, %01, %10 ;wall values for ID, N, E, S, W EndDataSection   #cellDWidth = 4   Structure mazeOutput vWall.s hWall.s EndStructure     ;setup reference values indexed by type and direction from current map cell Global Dim offset.POINT(#numOffsets, #numDirs) Define i, j For i = 0 To #numDirs For j = 0 To #numOffsets Read.i offset(j, i)\x: Read.i offset(j, i)\y Next Next   Global Dim wallvalue(#numDirs) For i = 0 To #numDirs: Read.i wallvalue(i): Next     Procedure makeDisplayMazeRow(Array mazeRow.mazeOutput(1), Array maze(2), y) ;modify mazeRow() to produce output of 2 strings showing the vertical walls above and horizontal walls across a given maze row Protected x, vWall.s, hWall.s Protected mazeWidth = ArraySize(maze(), 1), mazeHeight = ArraySize(maze(), 2)   vWall = "": hWall = "" For x = 0 To mazeWidth If maze(x, y) & wallvalue(#dir_N): vWall + "+ ": Else: vWall + "+---": EndIf If maze(x, y) & wallvalue(#dir_W): hWall + " ": Else: hWall + "| ": EndIf Next mazeRow(0)\vWall = Left(vWall, mazeWidth * #cellDWidth + 1) If y <> mazeHeight: mazeRow(0)\hWall = Left(hWall, mazeWidth * #cellDWidth + 1): Else: mazeRow(0)\hWall = "": EndIf EndProcedure   Procedure displayMaze(Array maze(2)) Protected x, y, vWall.s, hWall.s, mazeHeight = ArraySize(maze(), 2) Protected Dim mazeRow.mazeOutput(0)   For y = 0 To mazeHeight makeDisplayMazeRow(mazeRow(), maze(), y) PrintN(mazeRow(0)\vWall): PrintN(mazeRow(0)\hWall) Next EndProcedure   Procedure generateMaze(Array maze(2), mazeWidth, mazeHeight) Dim maze(mazeWidth, mazeHeight) ;Each cell specifies walls present above and to the left of it, ;array includes an extra row and column for the right and bottom walls Dim visited(mazeWidth + 1, mazeHeight + 1) ;Each cell represents a cell of the maze, an extra line of cells are included ;as padding around the representative cells for easy border detection   Protected i ;mark outside border as already visited (off limits) For i = 0 To mazeWidth visited(i + offset(#visited, #dir_N)\x, 0 + offset(#visited, #dir_N)\y) = #True visited(i + offset(#visited, #dir_S)\x, mazeHeight - 1 + offset(#visited, #dir_S)\y) = #True Next For i = 0 To mazeHeight visited(0 + offset(#visited, #dir_W)\x, i + offset(#visited, #dir_W)\y) = #True visited(mazeWidth - 1 + offset(#visited, #dir_E)\x, i + offset(#visited, #dir_E)\y) = #True Next   ;generate maze Protected x = Random(mazeWidth - 1), y = Random (mazeHeight - 1), cellCount, nextCell visited(x + offset(#visited, #dir_ID)\x, y + offset(#visited, #dir_ID)\y) = #True PrintN("Maze of size " + Str(mazeWidth) + " x " + Str(mazeHeight) + ", generation started at " + Str(x) + " x " + Str(y))   NewList stack.POINT() Dim unvisited(#numDirs - #firstDir) Repeat cellCount = 0 For i = #firstDir To #numDirs If Not visited(x + offset(#visited, i)\x, y + offset(#visited, i)\y) unvisited(cellCount) = i: cellCount + 1 EndIf Next   If cellCount nextCell = unvisited(Random(cellCount - 1)) visited(x + offset(#visited, nextCell)\x, y + offset(#visited, nextCell)\y) = #True maze(x + offset(#wall, nextCell)\x, y + offset(#wall, nextCell)\y) | wallvalue(nextCell)   If cellCount > 1 AddElement(stack()) stack()\x = x: stack()\y = y EndIf x + offset(#maze, nextCell)\x: y + offset(#maze, nextCell)\y ElseIf ListSize(stack()) > 0 x = stack()\x: y = stack()\y DeleteElement(stack()) Else Break ;end maze generation EndIf ForEver   ; ;mark random entry and exit point ; x = Random(mazeWidth - 1): y = Random(mazeHeight - 1) ; maze(x, 0) | wallvalue(#dir_N): maze(mazeWidth, y) | wallvalue(#dir_E) ProcedureReturn EndProcedure   If OpenConsole() Dim maze(0, 0) Define mazeWidth = Random(5) + 7: mazeHeight = Random(5) + 3 generateMaze(maze(), mazeWidth, mazeHeight) displayMaze(maze())   Print(#CRLF$ + #CRLF$ + "Press ENTER to exit"): Input() CloseConsole() EndIf
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#Ring
Ring
  # Project : Map range   decimals(1) al = 0 ah = 10 bl = -1 bh = 0 for n = 0 to 10 see "" + n + " maps to " + maprange(al, bl, n) + nl next   func maprange(al, bl, s) return bl + (s - al) * (bh - bl) / (ah - al)  
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#Ruby
Ruby
def map_range(a, b, s) af, al, bf, bl = a.first, a.last, b.first, b.last bf + (s - af)*(bl - bf).quo(al - af) end   (0..10).each{|s| puts "%s maps to %g" % [s, map_range(0..10, -1..0, s)]}
http://rosettacode.org/wiki/MD5
MD5
Task Encode a string using an MD5 algorithm.   The algorithm can be found on   Wikipedia. Optionally, validate your implementation by running all of the test values in   IETF RFC (1321)   for MD5. Additionally,   RFC 1321   provides more precise information on the algorithm than the Wikipedia article. Warning:   MD5 has known weaknesses, including collisions and forged signatures.   Users may consider a stronger alternative when doing production-grade cryptography, such as SHA-256 (from the SHA-2 family), or the upcoming SHA-3. If the solution on this page is a library solution, see   MD5/Implementation   for an implementation from scratch.
#PHP
PHP
$string = "The quick brown fox jumped over the lazy dog's back"; echo md5( $string );
http://rosettacode.org/wiki/Mandelbrot_set
Mandelbrot set
Mandelbrot set You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw the Mandelbrot set. Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
#Forth
Forth
500 value max-iter   : mandel ( gmp F: imin imax rmin rmax -- ) 0e 0e { F: imin F: imax F: rmin F: rmax F: Zr F: Zi } dup bheight 0 do i s>f dup bheight s>f f/ imax imin f- f* imin f+ TO Zi dup bwidth 0 do i s>f dup bwidth s>f f/ rmax rmin f- f* rmin f+ TO Zr Zr Zi max-iter begin 1- dup while fover fdup f* fover fdup f* fover fover f+ 4e f< while f- Zr f+ frot frot f* 2e f* Zi f+ repeat fdrop fdrop drop 0 \ for a pretty grayscale image, replace with: 255 max-iter */ else drop 255 then fdrop fdrop over i j rot g! loop loop drop ;   80 24 graymap dup -1e 1e -2e 1e mandel
http://rosettacode.org/wiki/Magic_squares_of_odd_order
Magic squares of odd order
A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers are usually (but not always) the first   N2   positive integers. A magic square whose rows and columns add up to a magic number but whose main diagonals do not, is known as a semimagic square. 8 1 6 3 5 7 4 9 2 Task For any odd   N,   generate a magic square with the integers   1 ──► N,   and show the results here. Optionally, show the magic number. You should demonstrate the generator by showing at least a magic square for   N = 5. Related tasks Magic squares of singly even order Magic squares of doubly even order See also MathWorld™ entry: Magic_square Odd Magic Squares (1728.org)
#Racket
Racket
#lang racket ;; Using "helpful formulae" in: ;; http://en.wikipedia.org/wiki/Magic_square#Method_for_constructing_a_magic_square_of_odd_order (define (squares n) n)   (define (last-no n) (sqr n))   (define (middle-no n) (/ (add1 (sqr n)) 2))   (define (M n) (* n (middle-no n)))   (define ((Ith-row-Jth-col n) I J) (+ (* (modulo (+ I J -1 (exact-floor (/ n 2))) n) n) (modulo (+ I (* 2 J) -2) n) 1))   (define (magic-square n) (define IrJc (Ith-row-Jth-col n)) (for/list ((I (in-range 1 (add1 n)))) (for/list ((J (in-range 1 (add1 n)))) (IrJc I J))))   (define (fmt-list-of-lists l-o-l width) (string-join (for/list ((row l-o-l)) (string-join (map (λ (x) (~a #:align 'right #:width width x)) row) " ")) "\n"))   (define (show-magic-square n) (format "MAGIC SQUARE ORDER:~a~%~a~%MAGIC NUMBER:~a~%" n (fmt-list-of-lists (magic-square n) (+ (order-of-magnitude (last-no n)) 1)) (M n)))   (displayln (show-magic-square 3)) (displayln (show-magic-square 5)) (displayln (show-magic-square 9))
http://rosettacode.org/wiki/Magic_squares_of_odd_order
Magic squares of odd order
A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers are usually (but not always) the first   N2   positive integers. A magic square whose rows and columns add up to a magic number but whose main diagonals do not, is known as a semimagic square. 8 1 6 3 5 7 4 9 2 Task For any odd   N,   generate a magic square with the integers   1 ──► N,   and show the results here. Optionally, show the magic number. You should demonstrate the generator by showing at least a magic square for   N = 5. Related tasks Magic squares of singly even order Magic squares of doubly even order See also MathWorld™ entry: Magic_square Odd Magic Squares (1728.org)
#Raku
Raku
17 24 1 8 15 23 5 7 14 16 4 6 13 20 22 10 12 19 21 3 11 18 25 2 9 The magic number is 65
http://rosettacode.org/wiki/Matrix_multiplication
Matrix multiplication
Task Multiply two matrices together. They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
#IDL
IDL
result = arr1 # arr2
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#Scheme
Scheme
(define (A k x1 x2 x3 x4 x5) (define (B) (set! k (- k 1)) (A k B x1 x2 x3 x4)) (if (<= k 0) (+ (x4) (x5)) (B)))   (A 10 (lambda () 1) (lambda () -1) (lambda () -1) (lambda () 1) (lambda () 0))
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#Sidef
Sidef
func a(k, x1, x2, x3, x4, x5) { func b { a(--k, b, x1, x2, x3, x4) }; k <= 0 ? (x4() + x5()) : b(); } say a(10, ->{1}, ->{-1}, ->{-1}, ->{1}, ->{0}); #=> -67
http://rosettacode.org/wiki/Matrix_transposition
Matrix transposition
Transpose an arbitrarily sized rectangular Matrix.
#Icon_and_Unicon
Icon and Unicon
procedure transpose_matrix (matrix) result := [] # for each column every (i := 1 to *matrix[1]) do { col := [] # extract the number in each row for that column every (row := !matrix) do put (col, row[i]) # and push that column as a row in the result matrix put (result, col) } return result end   procedure print_matrix (matrix) every (row := !matrix) do { every writes (!row || " ") write () } end   procedure main () matrix := [[1,2,3],[4,5,6]] write ("Start:") print_matrix (matrix) transposed := transpose_matrix (matrix) write ("Transposed:") print_matrix (transposed) end
http://rosettacode.org/wiki/Maze_generation
Maze generation
This page uses content from Wikipedia. The original article was at Maze generation algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) Task Generate and show a maze, using the simple Depth-first search algorithm. Start at a random cell. Mark the current cell as visited, and get a list of its neighbors. For each neighbor, starting with a randomly selected neighbor: If that neighbor hasn't been visited, remove the wall between this cell and that neighbor, and then recurse with that neighbor as the current cell. Related tasks Maze solving.
#Python
Python
from random import shuffle, randrange   def make_maze(w = 16, h = 8): vis = [[0] * w + [1] for _ in range(h)] + [[1] * (w + 1)] ver = [["| "] * w + ['|'] for _ in range(h)] + [[]] hor = [["+--"] * w + ['+'] for _ in range(h + 1)]   def walk(x, y): vis[y][x] = 1   d = [(x - 1, y), (x, y + 1), (x + 1, y), (x, y - 1)] shuffle(d) for (xx, yy) in d: if vis[yy][xx]: continue if xx == x: hor[max(y, yy)][x] = "+ " if yy == y: ver[y][max(x, xx)] = " " walk(xx, yy)   walk(randrange(w), randrange(h))   s = "" for (a, b) in zip(hor, ver): s += ''.join(a + ['\n'] + b + ['\n']) return s   if __name__ == '__main__': print(make_maze())
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#Rust
Rust
use std::ops::{Add, Sub, Mul, Div};   fn map_range<T: Copy>(from_range: (T, T), to_range: (T, T), s: T) -> T where T: Add<T, Output=T> + Sub<T, Output=T> + Mul<T, Output=T> + Div<T, Output=T> { to_range.0 + (s - from_range.0) * (to_range.1 - to_range.0) / (from_range.1 - from_range.0) }   fn main() { let input: Vec<f64> = vec![0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0]; let result = input.into_iter() .map(|x| map_range((0.0, 10.0), (-1.0, 0.0), x)) .collect::<Vec<f64>>(); print!("{:?}", result); }
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#Scala
Scala
def mapRange(a1:Double, a2:Double, b1:Double, b2:Double, x:Double):Double=b1+(x-a1)*(b2-b1)/(a2-a1)   for(i <- 0 to 10) println("%2d in [0, 10] maps to %5.2f in [-1, 0]".format(i, mapRange(0,10, -1,0, i)))
http://rosettacode.org/wiki/MD5
MD5
Task Encode a string using an MD5 algorithm.   The algorithm can be found on   Wikipedia. Optionally, validate your implementation by running all of the test values in   IETF RFC (1321)   for MD5. Additionally,   RFC 1321   provides more precise information on the algorithm than the Wikipedia article. Warning:   MD5 has known weaknesses, including collisions and forged signatures.   Users may consider a stronger alternative when doing production-grade cryptography, such as SHA-256 (from the SHA-2 family), or the upcoming SHA-3. If the solution on this page is a library solution, see   MD5/Implementation   for an implementation from scratch.
#PicoLisp
PicoLisp
(let Str "The quick brown fox jumped over the lazy dog's back" (pack (mapcar '((B) (pad 2 (hex B))) (native "libcrypto.so" "MD5" '(B . 16) Str (length Str) '(NIL (16))) ) ) )
http://rosettacode.org/wiki/Mandelbrot_set
Mandelbrot set
Mandelbrot set You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw the Mandelbrot set. Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
#Fortran
Fortran
program mandelbrot   implicit none integer , parameter :: rk = selected_real_kind (9, 99) integer , parameter :: i_max = 800 integer , parameter :: j_max = 600 integer , parameter :: n_max = 100 real (rk), parameter :: x_centre = -0.5_rk real (rk), parameter :: y_centre = 0.0_rk real (rk), parameter :: width = 4.0_rk real (rk), parameter :: height = 3.0_rk real (rk), parameter :: dx_di = width / i_max real (rk), parameter :: dy_dj = -height / j_max real (rk), parameter :: x_offset = x_centre - 0.5_rk * (i_max + 1) * dx_di real (rk), parameter :: y_offset = y_centre - 0.5_rk * (j_max + 1) * dy_dj integer, dimension (i_max, j_max) :: image integer :: i integer :: j integer :: n real (rk) :: x real (rk) :: y real (rk) :: x_0 real (rk) :: y_0 real (rk) :: x_sqr real (rk) :: y_sqr   do j = 1, j_max y_0 = y_offset + dy_dj * j do i = 1, i_max x_0 = x_offset + dx_di * i x = 0.0_rk y = 0.0_rk n = 0 do x_sqr = x ** 2 y_sqr = y ** 2 if (x_sqr + y_sqr > 4.0_rk) then image (i, j) = 255 exit end if if (n == n_max) then image (i, j) = 0 exit end if y = y_0 + 2.0_rk * x * y x = x_0 + x_sqr - y_sqr n = n + 1 end do end do end do open (10, file = 'out.pgm') write (10, '(a/ i0, 1x, i0/ i0)') 'P2', i_max, j_max, 255 write (10, '(i0)') image close (10)   end program mandelbrot
http://rosettacode.org/wiki/Magic_squares_of_odd_order
Magic squares of odd order
A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers are usually (but not always) the first   N2   positive integers. A magic square whose rows and columns add up to a magic number but whose main diagonals do not, is known as a semimagic square. 8 1 6 3 5 7 4 9 2 Task For any odd   N,   generate a magic square with the integers   1 ──► N,   and show the results here. Optionally, show the magic number. You should demonstrate the generator by showing at least a magic square for   N = 5. Related tasks Magic squares of singly even order Magic squares of doubly even order See also MathWorld™ entry: Magic_square Odd Magic Squares (1728.org)
#REXX
REXX
/*REXX program generates and displays magic squares (odd N will be a true magic square).*/ parse arg N . /*obtain the optional argument from CL.*/ if N=='' | N=="," then N=5 /*Not specified? Then use the default.*/ NN=N*N; w=length(NN) /*W: width of largest number (output).*/ r=1; c=(n+1) % 2 /*define the initial row and column.*/ @.=. /*assign a default value for entire @.*/ do j=1 for NN /* [↓] filling uses the Siamese method*/ if r<1 & c>N then do; r=r+2; c=c-1; end /*the row is under, column is over.*/ if r<1 then r=N /* " " " " make row=last. */ if r>N then r=1 /* " " " over, " " first.*/ if c>N then c=1 /* " column " over, " col=first.*/ if @.r.c\==. then do; r=min(N,r+2); c=max(1,c-1); end /*at the previous cell? */ @.r.c=j; r=r-1; c=c+1 /*assign # ───► cell; next row & column*/ end /*j*/ /* [↓] display square with aligned #'s*/ do r=1 for N; _= /*display one matrix row at a time. */ do c=1 for N; _=_ right(@.r.c, w) /*construct a row of the magic square. */ end /*c*/ say substr(_, 2) /*display a row of the magic square. */ end /*r*/ say /* [↓] If an odd square, show magic #.*/ if N//2 then say 'The magic number (or magic constant is): ' N * (NN+1) % 2 /*stick a fork in it, we're all done. */
http://rosettacode.org/wiki/Matrix_multiplication
Matrix multiplication
Task Multiply two matrices together. They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
#Idris
Idris
import Data.Vect   Matrix : Nat -> Nat -> Type -> Type Matrix m n t = Vect m (Vect n t)   multiply : Num t => Matrix m1 n t -> Matrix n m2 t -> Matrix m1 m2 t multiply a b = multiply' a (transpose b) where dot : Num t => Vect n t -> Vect n t -> t dot v1 v2 = sum $ map (\(s1, s2) => (s1 * s2)) (zip v1 v2)   multiply' : Num t => Matrix m1 n t -> Matrix m2 n t -> Matrix m1 m2 t multiply' (a::as) b = map (dot a) b :: multiply' as b multiply' [] _ = []
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#Smalltalk
Smalltalk
Number>>x1: x1 x2: x2 x3: x3 x4: x4 x5: x5 | b k | k := self. b := [ k := k - 1. k x1: b x2: x1 x3: x2 x4: x3 x5: x4 ]. ^k <= 0 ifTrue: [ x4 value + x5 value ] ifFalse: b 10 x1: [1] x2: [-1] x3: [-1] x4: [1] x5: [0]
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#Snap.21
Snap!
function a(k, x1, x2, x3, x4, x5) { let kk = { "k": k.k }; let b = function b() { kk.k--; return a(kk, b, x1, x2, x3, x4); }; return kk.k <= 0 ? x4() + x5() : b(); }   function x(n) { return function () { return n; }; }   print(a({ "k": 10 }, x(1), x(-1), x(-1), x(1), x(0)));
http://rosettacode.org/wiki/Matrix_transposition
Matrix transposition
Transpose an arbitrarily sized rectangular Matrix.
#IDL
IDL
m=[[1,1,1,1],[2, 4, 8, 16],[3, 9,27, 81],[5, 25,125, 625]] print,transpose(m)
http://rosettacode.org/wiki/Maze_generation
Maze generation
This page uses content from Wikipedia. The original article was at Maze generation algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) Task Generate and show a maze, using the simple Depth-first search algorithm. Start at a random cell. Mark the current cell as visited, and get a list of its neighbors. For each neighbor, starting with a randomly selected neighbor: If that neighbor hasn't been visited, remove the wall between this cell and that neighbor, and then recurse with that neighbor as the current cell. Related tasks Maze solving.
#Racket
Racket
  #lang racket   ;; the structure representing a maze of size NxM (struct maze (N M tbl))   ;; managing cell properties (define (connections tbl c) (dict-ref tbl c '()))   (define (connect! tbl c n) (dict-set! tbl c (cons n (connections tbl c))) (dict-set! tbl n (cons c (connections tbl n))))   (define (connected? tbl a b) (member a (connections tbl b)))   ;; Returns a maze of a given size ;; build-maze :: Index Index -> Maze (define (build-maze N M) (define tbl (make-hash)) (define (visited? tbl c) (dict-has-key? tbl c)) (define (neigbours c) (filter (match-lambda [(list i j) (and (<= 0 i (- N 1)) (<= 0 j (- M 1)))]) (for/list ([d '((0 1) (0 -1) (-1 0) (1 0))]) (map + c d))))  ; generate the maze (let move-to-cell ([c (list (random N) (random M))]) (for ([n (shuffle (neigbours c))] #:unless (visited? tbl n)) (connect! tbl c n) (move-to-cell n)))  ; return the result (maze N M tbl))  
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#Seed7
Seed7
$ include "seed7_05.s7i"; include "float.s7i";   const func float: mapRange (in float: a1, in float: a2, in float: b1, in float: b2, ref float: s) is return b1 + (s-a1)*(b2-b1)/(a2-a1);   const proc: main is func local var integer: number is 0; begin writeln("Mapping [0,10] to [-1,0] at intervals of 1:"); for number range 0 to 10 do writeln("f(" <& number <& ") = " <& mapRange(0.0, 10.0, -1.0, 0.0, flt(number)) digits 1); end for; end func;
http://rosettacode.org/wiki/Map_range
Map range
Given two ranges:   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   and   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]} ;   then a value   s {\displaystyle s}   in range   [ a 1 , a 2 ] {\displaystyle [a_{1},a_{2}]}   is linearly mapped to a value   t {\displaystyle t}   in range   [ b 1 , b 2 ] {\displaystyle [b_{1},b_{2}]}   where:   t = b 1 + ( s − a 1 ) ( b 2 − b 1 ) ( a 2 − a 1 ) {\displaystyle t=b_{1}+{(s-a_{1})(b_{2}-b_{1}) \over (a_{2}-a_{1})}} Task Write a function/subroutine/... that takes two ranges and a real number, and returns the mapping of the real number from the first to the second range. Use this function to map values from the range   [0, 10]   to the range   [-1, 0]. Extra credit Show additional idiomatic ways of performing the mapping, using tools available to the language.
#Sidef
Sidef
func map_range(a, b, x) { var (a1, a2, b1, b2) = (a.bounds, b.bounds); x-a1 * b2-b1 / a2-a1 + b1; }   var a = 0..10; var b = -1..0;   for x in a { say "#{x} maps to #{map_range(a, b, x)}"; }
http://rosettacode.org/wiki/MD5
MD5
Task Encode a string using an MD5 algorithm.   The algorithm can be found on   Wikipedia. Optionally, validate your implementation by running all of the test values in   IETF RFC (1321)   for MD5. Additionally,   RFC 1321   provides more precise information on the algorithm than the Wikipedia article. Warning:   MD5 has known weaknesses, including collisions and forged signatures.   Users may consider a stronger alternative when doing production-grade cryptography, such as SHA-256 (from the SHA-2 family), or the upcoming SHA-3. If the solution on this page is a library solution, see   MD5/Implementation   for an implementation from scratch.
#Pike
Pike
import String; import Crypto.MD5;   int main(){ write( string2hex( hash( "The quick brown fox jumped over the lazy dog's back" ) ) + "\n" ); }
http://rosettacode.org/wiki/Mandelbrot_set
Mandelbrot set
Mandelbrot set You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw the Mandelbrot set. Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
#Frink
Frink
  // Maximum levels for each pixel. levels = 60   // Create a random color for each level. colors = new array[[levels]] for a = 0 to levels-1 colors@a = new color[randomFloat[0,1], randomFloat[0,1], randomFloat[0,1]]   // Make this number smaller for higher resolution. stepsize = .005   g = new graphics g.antialiased[false]   for im = -1.2 to 1.2 step stepsize { imag = i * im for real = -2 to 1 step stepsize { C = real + imag z = 0 count = -1   do { z = z^2 + C count=count+1; } while abs[z] < 4 and count < levels   g.color[colors@((count-1) mod levels)] g.fillRectSize[real, im, stepsize, stepsize] } }   g.show[]  
http://rosettacode.org/wiki/Magic_squares_of_odd_order
Magic squares of odd order
A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers are usually (but not always) the first   N2   positive integers. A magic square whose rows and columns add up to a magic number but whose main diagonals do not, is known as a semimagic square. 8 1 6 3 5 7 4 9 2 Task For any odd   N,   generate a magic square with the integers   1 ──► N,   and show the results here. Optionally, show the magic number. You should demonstrate the generator by showing at least a magic square for   N = 5. Related tasks Magic squares of singly even order Magic squares of doubly even order See also MathWorld™ entry: Magic_square Odd Magic Squares (1728.org)
#Ring
Ring
  n=9 see "the square order is : " + n + nl for i=1 to n for j = 1 to n x = (i*2-j+n-1) % n*n + (i*2+j-2) % n + 1 see "" + x + " " next see nl next see "the magic number is : " + n*(n*n+1) / 2 + nl  
http://rosettacode.org/wiki/Magic_squares_of_odd_order
Magic squares of odd order
A magic square is an   NxN   square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column,   and   both long (main) diagonals are equal to the same sum (which is called the   magic number   or   magic constant). The numbers are usually (but not always) the first   N2   positive integers. A magic square whose rows and columns add up to a magic number but whose main diagonals do not, is known as a semimagic square. 8 1 6 3 5 7 4 9 2 Task For any odd   N,   generate a magic square with the integers   1 ──► N,   and show the results here. Optionally, show the magic number. You should demonstrate the generator by showing at least a magic square for   N = 5. Related tasks Magic squares of singly even order Magic squares of doubly even order See also MathWorld™ entry: Magic_square Odd Magic Squares (1728.org)
#Ruby
Ruby
def odd_magic_square(n) raise ArgumentError "Need odd positive number" if n.even? || n <= 0 n.times.map{|i| n.times.map{|j| n*((i+j+1+n/2)%n) + ((i+2*j-5)%n) + 1} } end   [3, 5, 9].each do |n| puts "\nSize #{n}, magic sum #{(n*n+1)/2*n}" fmt = "%#{(n*n).to_s.size + 1}d" * n odd_magic_square(n).each{|row| puts fmt % row} end  
http://rosettacode.org/wiki/Matrix_multiplication
Matrix multiplication
Task Multiply two matrices together. They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
#J
J
mp =: +/ .* NB. Matrix product   A =: ^/~>:i. 4 NB. Same A as in other examples (1 1 1 1, 2 4 8 16, 3 9 27 81,:4 16 64 256) B =:  %.A NB. Matrix inverse of A   '6.2' 8!:2 A mp B 1.00 0.00 0.00 0.00 0.00 1.00 0.00 0.00 0.00 0.00 1.00 0.00 0.00 0.00 0.00 1.00
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#Sparkling
Sparkling
function a(k, x1, x2, x3, x4, x5) { let kk = { "k": k.k }; let b = function b() { kk.k--; return a(kk, b, x1, x2, x3, x4); }; return kk.k <= 0 ? x4() + x5() : b(); }   function x(n) { return function () { return n; }; }   print(a({ "k": 10 }, x(1), x(-1), x(-1), x(1), x(0)));
http://rosettacode.org/wiki/Man_or_boy_test
Man or boy test
Man or boy test You are encouraged to solve this task according to the task description, using any language you may know. Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguish compilers that correctly implemented "recursion and non-local references" from those that did not. I have written the following simple routine, which may separate the 'man-compilers' from the 'boy-compilers' — Donald Knuth Task: Imitate Knuth's example in Algol 60 in another language, as far as possible. Details: Local variables of routines are often kept in activation records (also call frames). In many languages, these records are kept on a call stack. In Algol (and e.g. in Smalltalk), they are allocated on a heap instead. Hence it is possible to pass references to routines that still can use and update variables from their call environment, even if the routine where those variables are declared already returned. This difference in implementations is sometimes called the Funarg Problem. In Knuth's example, each call to A allocates an activation record for the variable A. When B is called from A, any access to k now refers to this activation record. Now B in turn calls A, but passes itself as an argument. This argument remains bound to the activation record. This call to A also "shifts" the variables xi by one place, so eventually the argument B (still bound to its particular activation record) will appear as x4 or x5 in a call to A. If this happens when the expression x4 + x5 is evaluated, then this will again call B, which in turn will update k in the activation record it was originally bound to. As this activation record is shared with other instances of calls to A and B, it will influence the whole computation. So all the example does is to set up a convoluted calling structure, where updates to k can influence the behavior in completely different parts of the call tree. Knuth used this to test the correctness of the compiler, but one can of course also use it to test that other languages can emulate the Algol behavior correctly. If the handling of activation records is correct, the computed value will be −67. Performance and Memory: Man or Boy is intense and can be pushed to challenge any machine. Memory (both stack and heap) not CPU time is the constraining resource as the recursion creates a proliferation activation records which will quickly exhaust memory and present itself through a stack error. Each language may have ways of adjusting the amount of memory or increasing the recursion depth. Optionally, show how you would make such adjustments. The table below shows the result, call depths, and total calls for a range of k: k 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A 1 0 -2 0 1 0 1 -1 -10 -30 -67 -138 -291 -642 -1,446 -3,250 -7,244 -16,065 -35,601 -78,985 -175,416 -389,695 -865,609 -1,922,362 -4,268,854 -9,479,595 -21,051,458 -46,750,171 -103,821,058 -230,560,902 -512,016,658 A called 1 2 3 4 8 18 38 80 167 347 722 1,509 3,168 6,673 14,091 29,825 63,287 134,652 287,264 614,442 1,317,533 2,831,900 6,100,852 13,172,239 28,499,827 61,786,266 134,202,509 292,011,464       A depth 1 2 3 4 8 16 32 64 128 256 512 1,024 2,048 4,096 8,192 16,384 32,768 65,536 131,072 262,144 524,288 1,048,576 2,097,152 4,194,304 8,388,608             B called 0 1 2 3 7 17 37 79 166 346 721 1,508 3,167 6,672 14,090 29,824 63,286 134,651 287,263 614,441 1,317,532 2,831,899 6,100,851 13,172,238 28,499,826             B depth 0 1 2 3 7 15 31 63 127 255 511 1,023 2,047 4,095 8,191 16,383 32,767 65,535 131,071 262,143 524,287 1,048,575 2,097,151 4,194,303 8,388,607             Related tasks   Jensen's Device
#Standard_ML
Standard ML
fun a (k, x1, x2, x3, x4, x5) = if k <= 0 then x4 () + x5 () else let val m = ref k fun b () = ( m := !m - 1; a (!m, b, x1, x2, x3, x4) ) in b () end   val () = print (Int.toString (a (10, fn () => 1, fn () => ~1, fn () => ~1, fn () => 1, fn () => 0)) ^ "\n")