Update README.md

README.md

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 ---
-license: apache-2.0
+license: cc-by-4.0
+language:
+  - en
+pretty_name: LeetCode Problems Labelled by Solution Pattern (Sample)
+size_categories:
+  - n<1K
+task_categories:
+  - text-classification
+tags:
+  - code
+  - algorithms
+  - programming-problems
+  - technical-interviews
+  - leetcode
+  - taxonomy
+configs:
+  - config_name: default
+    data_files:
+      - split: train
+        path: data/train.jsonl
 ---
+
+# LeetCode Problems Labelled by Solution Pattern (Sample)
+
+A 100-problem sample of LeetCode problems annotated with the **algorithmic technique that solves
+them**, rather than the topic tag that describes what they are about.
+
+LeetCode's own tags answer "what is this problem about" — `Array`, `String`, `Hash Table`. That is
+not the same question as "how is it solved". Both *Two Sum* and *Longest Substring Without Repeating
+Characters* are tagged `Hash Table`, but one is a complement lookup and the other is a sliding window
+with a seen-set. This dataset adds a `solution_archetype` field that answers the second question.
+
+The full corpus this sample is drawn from covers 3,000 problems across 29 archetypes.
+
+## Dataset structure
+
+One JSON object per line in `data/train.jsonl`:
+
+| field | type | description |
+| --- | --- | --- |
+| `problem_number` | int | The problem's number on LeetCode |
+| `title` | string | Problem title |
+| `slug` | string | URL slug |
+| `difficulty` | string | `Easy`, `Medium` or `Hard` |
+| `topic_tags` | list[string] | LeetCode's own topic tags, unmodified |
+| `solution_archetype` | string | **The annotation.** The technique that solves the problem |
+| `has_reference_solution` | bool | Whether a worked reference solution exists for this problem |
+| `leetcode_url` | string | Canonical problem URL on leetcode.com |
+| `pattern_reference` | string \| null | Write-up of the archetype, where one exists |
+
+### Sample row
+
+```json
+{
+  "problem_number": 1,
+  "title": "Two Sum",
+  "slug": "two-sum",
+  "difficulty": "Easy",
+  "topic_tags": ["Array", "Hash Table"],
+  "solution_archetype": "hash-map",
+  "has_reference_solution": true,
+  "leetcode_url": "https://leetcode.com/problems/two-sum/",
+  "pattern_reference": "https://www.stealthinterview.ai/leetcode/patterns/hash-map"
+}
+```
+
+### Composition of this sample
+
+100 problems, stratified to cover as many archetypes as possible while keeping the difficulty mix of
+the source corpus: **21 Easy / 63 Medium / 16 Hard**, spanning **29 distinct archetypes**. Selection
+is deterministic — problems are taken in ascending number, round-robin across archetypes — so the
+sample is reproducible rather than a random draw. Premium-only problems are excluded, because their
+statements are not publicly checkable.
+
+## Usage
+
+```python
+from datasets import load_dataset
+
+ds = load_dataset("<your-username>/leetcode-solution-patterns-sample", split="train")
+
+# Problems solved by a monotonic stack
+mono = ds.filter(lambda r: r["solution_archetype"] == "monotonic-stack")
+
+# Where LeetCode's tag and the solving technique disagree
+mismatch = ds.filter(
+    lambda r: "Hash Table" in r["topic_tags"] and r["solution_archetype"] != "hash-map"
+)
+```
+
+## Provenance and what is actually original here
+
+This distinction matters, so it is stated plainly:
+
+- **Not original, and not owned by this dataset:** problem numbers, titles, slugs, difficulty ratings
+  and topic tags. These are factual references to problems hosted on LeetCode.
+- **Original:** the `solution_archetype` labels and the taxonomy of 29 archetypes they are drawn
+  from. These were derived by analysing solution structure across the corpus and are the reason this
+  dataset exists.
+
+**No problem statements, test cases, editorial content or LeetCode solutions are included in this
+dataset.** Only metadata and links back to the canonical problem pages. If you need the problem text,
+follow `leetcode_url`.
+
+LeetCode is a trademark of its respective owner. This dataset is not affiliated with, endorsed by, or
+sponsored by LeetCode.
+
+## Licence
+
+The **annotations** — `solution_archetype` and the taxonomy — are released under
+[CC BY 4.0](https://creativecommons.org/licenses/by/4.0/). Attribution is appreciated if you use the
+labels in research or a downstream dataset.
+
+The referenced problem metadata is factual information about a third-party platform and is not
+claimed under this licence.
+
+## Limitations
+
+- **One archetype per problem.** Many problems admit more than one valid approach; the label records
+  the technique the reference solution used, not the only one that works.
+- **`bespoke` is a real category, not a fallback for hard problems.** It marks problems whose
+  solution does not generalise to a reusable pattern.
+- **The taxonomy is opinionated.** Where you draw the line between `stack` and `monotonic-stack`, or
+  `dfs` and `graph-traversal`, is a judgement call. The boundaries here are consistent within the
+  corpus but are not a standard anyone else has ratified.
+- **Sample, not corpus.** 100 of 3,000. Frequencies here will not match the full distribution.
+
+## Source
+
+Built from the problem library at
+[stealthinterview.ai/leetcode](https://www.stealthinterview.ai/leetcode), which organises the full
+3,000-problem set by solving technique. The archetype taxonomy and the per-technique write-ups —
+including the template, complexity and applicable problems for each — are documented at
+[stealthinterview.ai/leetcode/patterns](https://www.stealthinterview.ai/leetcode/patterns).
+
+## Citation
+
+```bibtex
+@misc{leetcode_solution_patterns_2026,
+  title  = {LeetCode Problems Labelled by Solution Pattern},
+  year   = {2026},
+  url    = {https://www.stealthinterview.ai/leetcode/patterns},
+  note   = {Sample of 100 problems annotated with solving technique}
+}
+```