feat: add Ransom Note

Author: wislertt

.templates/leetcode/json/ransom_note.json

@@ -0,0 +1,44 @@
+{
+    "problem_name": "ransom_note",
+    "solution_class_name": "Solution",
+    "problem_number": "383",
+    "problem_title": "Ransom Note",
+    "difficulty": "Easy",
+    "topics": "Hash Table, String, Counting",
+    "tags": ["grind-75"],
+    "readme_description": "Given two strings `ransomNote` and `magazine`, return `true` if `ransomNote` can be constructed by using the letters from `magazine` and `false` otherwise.\n\nEach letter in `magazine` can only be used once in `ransomNote`.",
+    "readme_examples": [
+        { "content": "```\nInput: ransomNote = \"a\", magazine = \"b\"\nOutput: false\n```" },
+        { "content": "```\nInput: ransomNote = \"aa\", magazine = \"ab\"\nOutput: false\n```" },
+        { "content": "```\nInput: ransomNote = \"aa\", magazine = \"aab\"\nOutput: true\n```" }
+    ],
+    "readme_constraints": "- 1 <= ransomNote.length, magazine.length <= 10^5\n- ransomNote and magazine consist of lowercase English letters.",
+    "readme_additional": "",
+    "solution_imports": "",
+    "solution_methods": [
+        {
+            "name": "can_construct",
+            "parameters": "ransom_note: str, magazine: str",
+            "return_type": "bool",
+            "dummy_return": "False"
+        }
+    ],
+    "test_imports": "import pytest\nfrom leetcode_py.test_utils import logged_test\nfrom .solution import Solution",
+    "test_class_name": "RansomNote",
+    "test_helper_methods": [
+        { "name": "setup_method", "parameters": "", "body": "self.solution = Solution()" }
+    ],
+    "test_methods": [
+        {
+            "name": "test_can_construct",
+            "parametrize": "ransom_note, magazine, expected",
+            "parametrize_typed": "ransom_note: str, magazine: str, expected: bool",
+            "test_cases": "[('a', 'b', False), ('aa', 'ab', False), ('aa', 'aab', True), ('aab', 'baa', True)]",
+            "body": "result = self.solution.can_construct(ransom_note, magazine)\nassert result == expected"
+        }
+    ],
+    "playground_imports": "from solution import Solution",
+    "playground_test_case": "# Example test case\nransom_note = 'aa'\nmagazine = 'aab'\nexpected = True",
+    "playground_execution": "result = Solution().can_construct(ransom_note, magazine)\nresult",
+    "playground_assertion": "assert result == expected"
+}

.templates/leetcode/{{cookiecutter.problem_name}}/solution.py

@@ -1,5 +1,5 @@
 {{cookiecutter.solution_imports}}
-
+{# TODO: add helper class like class Node: .... #}
 class {{cookiecutter.solution_class_name}}:
     {%- for _, methods in cookiecutter._solution_methods | dictsort %}
     {%- for method in methods %}

Makefile

@@ -1,5 +1,5 @@
 PYTHON_VERSION = 3.13
-PROBLEM ?= merge_k_sorted_lists
+PROBLEM ?= ransom_note
 FORCE ?= 0
 COMMA := ,
 

leetcode/ransom_note/README.md

@@ -0,0 +1,41 @@
+# Ransom Note
+
+**Difficulty:** Easy
+**Topics:** Hash Table, String, Counting
+**Tags:** grind-75
+
+**LeetCode:** [Problem 383](https://leetcode.com/problems/ransom-note/description/)
+
+## Problem Description
+
+Given two strings `ransomNote` and `magazine`, return `true` if `ransomNote` can be constructed by using the letters from `magazine` and `false` otherwise.
+
+Each letter in `magazine` can only be used once in `ransomNote`.
+
+## Examples
+
+### Example 1:
+
+```
+Input: ransomNote = "a", magazine = "b"
+Output: false
+```
+
+### Example 2:
+
+```
+Input: ransomNote = "aa", magazine = "ab"
+Output: false
+```
+
+### Example 3:
+
+```
+Input: ransomNote = "aa", magazine = "aab"
+Output: true
+```
+
+## Constraints
+
+- 1 <= ransomNote.length, magazine.length <= 10^5
+- ransomNote and magazine consist of lowercase English letters.

leetcode/ransom_note/__init__.py

@@ -0,0 +1,80 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "imports",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from solution import Solution"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "setup",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Example test case\n",
+    "ransom_note = \"aa\"\n",
+    "magazine = \"aab\"\n",
+    "expected = True"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "id": "execute",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "True"
+      ]
+     },
+     "execution_count": 3,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "result = Solution().can_construct(ransom_note, magazine)\n",
+    "result"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "test",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "assert 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/ransom_note/playground.ipynb

@@ -0,0 +1,18 @@
+from collections import Counter
+
+
+class Solution:
+    # Time: O(m + n) where m = magazine length, n = ransom_note length
+    # Space: O(1) - at most 26 lowercase letters
+    def can_construct(self, ransom_note: str, magazine: str) -> bool:
+        if len(ransom_note) > len(magazine):
+            return False
+
+        magazine_count = Counter(magazine)
+
+        for char in ransom_note:
+            if magazine_count[char] == 0:
+                return False
+            magazine_count[char] -= 1
+
+        return True

leetcode/ransom_note/solution.py

@@ -0,0 +1,38 @@
+import pytest
+
+from leetcode_py.test_utils import logged_test
+
+from .solution import Solution
+
+
+class TestRansomNote:
+    def setup_method(self):
+        self.solution = Solution()
+
+    @pytest.mark.parametrize(
+        "ransom_note, magazine, expected",
+        [
+            # Original test cases
+            ("a", "b", False),
+            ("aa", "ab", False),
+            ("aa", "aab", True),
+            ("aab", "baa", True),
+            # Edge cases
+            ("", "", True),  # Both empty
+            ("", "abc", True),  # Empty ransom note
+            ("a", "", False),  # Empty magazine
+            ("a", "a", True),  # Single char match
+            ("ab", "a", False),  # Ransom longer than magazine
+            # More complex cases
+            ("abc", "aabbcc", True),  # Multiple of each char
+            ("aab", "baa", True),  # Same chars, different order
+            ("aaa", "aa", False),  # Not enough of same char
+            ("abcd", "dcba", True),  # All different chars
+            ("hello", "helloworld", True),  # Ransom is substring
+            ("world", "hello", False),  # Missing chars
+        ],
+    )
+    @logged_test
+    def test_can_construct(self, ransom_note: str, magazine: str, expected: bool):
+        result = self.solution.can_construct(ransom_note, magazine)
+        assert result == expected