feat: add two_sum (#36)

Author: wisarootl

.github/workflows/ci-test-reproducibility.yml

@@ -35,6 +35,40 @@ jobs:
             - name: Install dependencies
               run: poetry install --no-interaction --no-ansi
 
+            - name: Cache Graphviz installation
+              id: cache-graphviz
+              uses: actions/cache@0400d5f644dc74513175e3cd8d07132dd4860809 # v4.2.4
+              with:
+                  path: ~/graphviz-cache
+                  key: graphviz-installed-${{ runner.os }}
+
+            - name: Install Graphviz
+              run: |
+                  if [ "${{ steps.cache-graphviz.outputs.cache-hit }}" = "true" ]; then
+                      sudo cp ~/graphviz-cache/bin/* /usr/bin/ 2>/dev/null || true
+                      sudo cp ~/graphviz-cache/lib/* /usr/lib/x86_64-linux-gnu/ 2>/dev/null || true
+                      sudo cp -r ~/graphviz-cache/share/graphviz /usr/share/ 2>/dev/null || true
+                      sudo cp -r ~/graphviz-cache/lib/graphviz /usr/lib/x86_64-linux-gnu/ 2>/dev/null || true
+                      sudo ldconfig
+                      sudo dot -c
+                  else
+                      sudo apt-get update
+                      sudo apt-get install -y graphviz
+                      mkdir -p ~/graphviz-cache/{bin,lib,share}
+                      cp /usr/bin/{dot,neato,twopi,circo,fdp,sfdp,patchwork,osage} ~/graphviz-cache/bin/ 2>/dev/null || true
+                      cp /usr/lib/x86_64-linux-gnu/lib{gvc,cgraph,cdt,pathplan,gvpr,lab-gamut,ann,gts}* ~/graphviz-cache/lib/ 2>/dev/null || true
+                      cp -r /usr/lib/x86_64-linux-gnu/graphviz ~/graphviz-cache/lib/ 2>/dev/null || true
+                      cp -r /usr/share/graphviz ~/graphviz-cache/share/ 2>/dev/null || true
+                  fi
+
+            - name: Check test case count
+              run: poetry run python .templates/check_test_cases.py --threshold=10 --max=100
+
+            - name: Backup existing problems
+              run: |
+                  mkdir -p .cache
+                  cp -r leetcode .cache/
+
             - name: Delete existing problems
               run: rm -rf leetcode/*/
 
@@ -46,3 +80,15 @@ jobs:
 
             - name: Run linting to verify reproducibility
               run: make lint
+
+            - name: Copy solution files from backup
+              run: |
+                  for problem in .cache/leetcode/*/; do
+                      problem_name=$(basename "$problem")
+                      if [ -f "$problem/solution.py" ] && [ -d "leetcode/$problem_name" ]; then
+                          cp "$problem/solution.py" "leetcode/$problem_name/solution.py"
+                      fi
+                  done
+
+            - name: Run tests
+              run: make test

.templates/check_test_cases.py

@@ -82,10 +82,14 @@ def main(
             typer.echo(f"Invalid max_results value: {max_results}", err=True)
             raise typer.Exit(1)
 
-    typer.echo(f"Files with ≤{threshold} test cases ({len(filtered_files)} total):")
+    typer.echo(f"Problems with ≤{threshold} test cases ({len(filtered_files)} total):")
     for filename, count in filtered_files:
         typer.echo(f"{filename}: {count} test cases")
 
+    # Exit with non-zero code if any files found
+    if filtered_files:
+        raise typer.Exit(1)
+
 
 if __name__ == "__main__":
     typer.run(main)

.templates/leetcode/json/two_sum.json

@@ -0,0 +1,63 @@
+{
+    "problem_name": "two_sum",
+    "solution_class_name": "Solution",
+    "problem_number": "1",
+    "problem_title": "Two Sum",
+    "difficulty": "Easy",
+    "topics": "Array, Hash Table",
+    "_tags": { "list": ["grind-75"] },
+    "readme_description": "Given an array of integers `nums` and an integer `target`, return indices of the two numbers such that they add up to `target`.\n\nYou may assume that each input would have exactly one solution, and you may not use the same element twice.\n\nYou can return the answer in any order.",
+    "_readme_examples": {
+        "list": [
+            {
+                "content": "```\nInput: nums = [2,7,11,15], target = 9\nOutput: [0,1]\n```\n**Explanation:** Because nums[0] + nums[1] == 9, we return [0, 1]."
+            },
+            { "content": "```\nInput: nums = [3,2,4], target = 6\nOutput: [1,2]\n```" },
+            { "content": "```\nInput: nums = [3,3], target = 6\nOutput: [0,1]\n```" }
+        ]
+    },
+    "readme_constraints": "- 2 <= nums.length <= 10^4\n- -10^9 <= nums[i] <= 10^9\n- -10^9 <= target <= 10^9\n- Only one valid answer exists.",
+    "readme_additional": "**Follow-up:** Can you come up with an algorithm that is less than O(n^2) time complexity?",
+    "helpers_imports": "",
+    "helpers_content": "",
+    "helpers_run_name": "two_sum",
+    "helpers_run_signature": "(solution_class: type, nums: list[int], target: int)",
+    "helpers_run_body": "    implementation = solution_class()\n    return implementation.two_sum(nums, target)",
+    "helpers_assert_name": "two_sum",
+    "helpers_assert_signature": "(result: list[int], expected: list[int]) -> bool",
+    "helpers_assert_body": "    assert result == expected\n    return True",
+    "solution_imports": "",
+    "solution_contents": "",
+    "solution_class_content": "",
+    "test_imports": "import pytest\nfrom leetcode_py.test_utils import logged_test\nfrom .helpers import assert_two_sum, run_two_sum\nfrom .solution import Solution",
+    "test_content": "",
+    "test_class_name": "TwoSum",
+    "test_class_content": "    def setup_method(self):\n        self.solution = Solution()",
+    "_solution_methods": {
+        "list": [
+            {
+                "name": "two_sum",
+                "signature": "(self, nums: list[int], target: int) -> list[int]",
+                "body": "        # TODO: Implement two_sum\n        return []"
+            }
+        ]
+    },
+    "_test_helper_methods": {
+        "list": [{ "name": "setup_method", "parameters": "", "body": "self.solution = Solution()" }]
+    },
+    "_test_methods": {
+        "list": [
+            {
+                "name": "test_two_sum",
+                "signature": "(self, nums: list[int], target: int, expected: list[int])",
+                "parametrize": "nums, target, expected",
+                "test_cases": "[([2, 7, 11, 15], 9, [0, 1]), ([3, 2, 4], 6, [1, 2]), ([3, 3], 6, [0, 1]), ([2, 5, 5, 11], 10, [1, 2]), ([1, 2, 3, 4, 5], 8, [2, 4]), ([0, 4, 3, 0], 0, [0, 3]), ([-1, -2, -3, -4, -5], -8, [2, 4]), ([1, 3, 4, 2], 6, [2, 3]), ([5, 75, 25], 100, [1, 2]), ([-3, 4, 3, 90], 0, [0, 2]), ([1, 1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 2], 6, [5, 11]), ([2, 1, 9, 4, 4, 56, 90, 3], 8, [3, 4]), ([89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99], 185, [3, 4]), ([-1000000000, 1000000000], 0, [0, 1]), ([0, 1], 1, [0, 1]), ([1, 2], 5, []), ([3, 5, 7], 1, []), ([10, 20, 30], 15, [])]",
+                "body": "        result = run_two_sum(Solution, nums, target)\n        assert_two_sum(result, expected)"
+            }
+        ]
+    },
+    "playground_imports": "from helpers import run_two_sum, assert_two_sum\nfrom solution import Solution",
+    "playground_setup": "# Example test case\nnums = [2, 7, 11, 15]\ntarget = 9\nexpected = [0, 1]",
+    "playground_run": "result = run_two_sum(Solution, nums, target)\nresult",
+    "playground_assert": "assert_two_sum(result, expected)"
+}

Makefile

@@ -1,5 +1,5 @@
 PYTHON_VERSION = 3.13
-PROBLEM ?= min_stack
+PROBLEM ?= two_sum
 FORCE ?= 0
 COMMA := ,
 

leetcode/two_sum/README.md

@@ -0,0 +1,49 @@
+# Two Sum
+
+**Difficulty:** Easy
+**Topics:** Array, Hash Table
+**Tags:** grind-75
+
+**LeetCode:** [Problem 1](https://leetcode.com/problems/two-sum/description/)
+
+## Problem Description
+
+Given an array of integers `nums` and an integer `target`, return indices of the two numbers such that they add up to `target`.
+
+You may assume that each input would have exactly one solution, and you may not use the same element twice.
+
+You can return the answer in any order.
+
+## Examples
+
+### Example 1:
+
+```
+Input: nums = [2,7,11,15], target = 9
+Output: [0,1]
+```
+
+**Explanation:** Because nums[0] + nums[1] == 9, we return [0, 1].
+
+### Example 2:
+
+```
+Input: nums = [3,2,4], target = 6
+Output: [1,2]
+```
+
+### Example 3:
+
+```
+Input: nums = [3,3], target = 6
+Output: [0,1]
+```
+
+## Constraints
+
+- 2 <= nums.length <= 10^4
+- -10^9 <= nums[i] <= 10^9
+- -10^9 <= target <= 10^9
+- Only one valid answer exists.
+
+**Follow-up:** Can you come up with an algorithm that is less than O(n^2) time complexity?

leetcode/two_sum/__init__.py

@@ -0,0 +1,8 @@
+def run_two_sum(solution_class: type, nums: list[int], target: int):
+    implementation = solution_class()
+    return implementation.two_sum(nums, target)
+
+
+def assert_two_sum(result: list[int], expected: list[int]) -> bool:
+    assert result == expected
+    return True

leetcode/two_sum/helpers.py

@@ -0,0 +1,92 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "imports",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from helpers import assert_two_sum, run_two_sum\n",
+    "from solution import Solution"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "setup",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Example test case\n",
+    "nums = [2, 7, 11, 15]\n",
+    "target = 9\n",
+    "expected = [0, 1]"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "id": "run",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "[0, 1]"
+      ]
+     },
+     "execution_count": 3,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "result = run_two_sum(Solution, nums, target)\n",
+    "result"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "assert",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "True"
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "assert_two_sum(result, expected)"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "leetcode-py-py3.13",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.13.7"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}

leetcode/two_sum/playground.ipynb

@@ -0,0 +1,12 @@
+class Solution:
+
+    # Time: O(n)
+    # Space: O(n)
+    def two_sum(self, nums: list[int], target: int) -> list[int]:
+        seen: dict[int, int] = {}
+        for i, num in enumerate(nums):
+            complement = target - num
+            if complement in seen:
+                return [seen[complement], i]
+            seen[num] = i
+        return []

leetcode/two_sum/solution.py

@@ -0,0 +1,39 @@
+import pytest
+
+from leetcode_py.test_utils import logged_test
+
+from .helpers import assert_two_sum, run_two_sum
+from .solution import Solution
+
+
+class TestTwoSum:
+    def setup_method(self):
+        self.solution = Solution()
+
+    @logged_test
+    @pytest.mark.parametrize(
+        "nums, target, expected",
+        [
+            ([2, 7, 11, 15], 9, [0, 1]),
+            ([3, 2, 4], 6, [1, 2]),
+            ([3, 3], 6, [0, 1]),
+            ([2, 5, 5, 11], 10, [1, 2]),
+            ([1, 2, 3, 4, 5], 8, [2, 4]),
+            ([0, 4, 3, 0], 0, [0, 3]),
+            ([-1, -2, -3, -4, -5], -8, [2, 4]),
+            ([1, 3, 4, 2], 6, [2, 3]),
+            ([5, 75, 25], 100, [1, 2]),
+            ([-3, 4, 3, 90], 0, [0, 2]),
+            ([1, 1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 2], 6, [5, 11]),
+            ([2, 1, 9, 4, 4, 56, 90, 3], 8, [3, 4]),
+            ([89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99], 185, [3, 4]),
+            ([-1000000000, 1000000000], 0, [0, 1]),
+            ([0, 1], 1, [0, 1]),
+            ([1, 2], 5, []),
+            ([3, 5, 7], 1, []),
+            ([10, 20, 30], 15, []),
+        ],
+    )
+    def test_two_sum(self, nums: list[int], target: int, expected: list[int]):
+        result = run_two_sum(Solution, nums, target)
+        assert_two_sum(result, expected)