Add Restaurant problem solution and SRI calculation script

Author: myoshi2891

Mathematics/Fundamentals/HackerRank/Claude/Easy/Restaurant/Restaurant.ipynb

@@ -0,0 +1,131 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "id": "b85ac912",
+   "metadata": {},
+   "source": [
+    "# 問題分析結果\n",
+    "\n",
+    "## 1. 多角的問題分析\n",
+    "\n",
+    "### 競技プログラミング視点\n",
+    "- **制約**: `1 ≤ l, b ≤ 1000` → 小規模入力、数学的解法が最適\n",
+    "- **核心**: 最大の正方形サイズ = `gcd(l, b)`、個数 = 面積 / 正方形面積\n",
+    "\n",
+    "### 業務開発視点\n",
+    "- **型安全性**: 入力は整数、GCD計算で標準ライブラリ活用\n",
+    "- **エッジケース**: `l = b` の場合（正方形そのもの）も正しく処理\n",
+    "\n",
+    "### Python特有考慮\n",
+    "- `math.gcd()` は C実装で高速（O(log min(l,b))）\n",
+    "- 整数除算 `//` で型安全性確保\n",
+    "\n",
+    "---\n",
+    "\n",
+    "## 2. アルゴリズム比較表\n",
+    "\n",
+    "| アプローチ | 時間計算量 | 空間計算量 | Python実装コスト | 可読性 | 標準ライブラリ活用 | 備考 |\n",
+    "|---------|---------|---------|------------|-------|--------------|-----|\n",
+    "| GCD利用 | O(log n) | O(1) | 低 | ★★★ | math.gcd | **最適解** |\n",
+    "| 全探索 | O(min(l,b)) | O(1) | 中 | ★★☆ | なし | 非効率 |\n",
+    "\n",
+    "---\n",
+    "\n",
+    "## 3. 採用アルゴリズムと根拠\n",
+    "\n",
+    "### 数学的洞察\n",
+    "1. 正方形の一辺は `l` と `b` の両方で割り切れる必要がある\n",
+    "2. 最大サイズ = 最大公約数 `g = gcd(l, b)`\n",
+    "3. 個数 = `(l / g) × (b / g) = (l × b) / g²`\n",
+    "\n",
+    "### 検証\n",
+    "- 例1: `l=2, b=2` → `g=2` → `(2×2)/(2×2) = 1` ✓\n",
+    "- 例2: `l=6, b=9` → `g=3` → `(6×9)/(3×3) = 6` ✓\n",
+    "\n",
+    "---\n",
+    "\n",
+    "## 4. HackerRankでの回答フォーマット\n",
+    "\n",
+    "```python\n",
+    "#!/bin/python3\n",
+    "\n",
+    "import math\n",
+    "import os\n",
+    "import random\n",
+    "import re\n",
+    "import sys\n",
+    "\n",
+    "#\n",
+    "# Complete the 'restaurant' function below.\n",
+    "#\n",
+    "# The function is expected to return an INTEGER.\n",
+    "# The function accepts following parameters:\n",
+    "#  1. INTEGER l\n",
+    "#  2. INTEGER b\n",
+    "#\n",
+    "\n",
+    "def restaurant(l: int, b: int) -> int:\n",
+    "    \"\"\"\n",
+    "    パンを最大サイズの正方形に切り分けた際の個数を計算\n",
+    "    \n",
+    "    アルゴリズム:\n",
+    "    - 正方形の最大サイズ = gcd(l, b)\n",
+    "    - 個数 = (l * b) / gcd(l, b)^2\n",
+    "    \n",
+    "    Time Complexity: O(log(min(l, b)))\n",
+    "    Space Complexity: O(1)\n",
+    "    \n",
+    "    Args:\n",
+    "        l: パンの長さ\n",
+    "        b: パンの幅\n",
+    "    \n",
+    "    Returns:\n",
+    "        最大サイズの正方形の個数\n",
+    "    \"\"\"\n",
+    "    g = math.gcd(l, b)\n",
+    "    return (l * b) // (g * g)\n",
+    "\n",
+    "\n",
+    "if __name__ == '__main__':\n",
+    "    fptr = open(os.environ['OUTPUT_PATH'], 'w')\n",
+    "\n",
+    "    t = int(input().strip())\n",
+    "\n",
+    "    for t_itr in range(t):\n",
+    "        first_multiple_input = input().rstrip().split()\n",
+    "\n",
+    "        l = int(first_multiple_input[0])\n",
+    "\n",
+    "        b = int(first_multiple_input[1])\n",
+    "\n",
+    "        result = restaurant(l, b)\n",
+    "\n",
+    "        fptr.write(str(result) + '\\n')\n",
+    "\n",
+    "    fptr.close()\n",
+    "```\n",
+    "\n",
+    "---\n",
+    "\n",
+    "## 5. Python最適化ポイント\n",
+    "\n",
+    "✅ **`math.gcd()` 活用**: C実装の高速GCD  \n",
+    "✅ **整数除算 `//`**: 型安全性保証  \n",
+    "✅ **シンプルな実装**: 可読性とパフォーマンス両立  \n",
+    "✅ **型ヒント**: pylanceエラー回避  \n",
+    "\n",
+    "### 計算量保証\n",
+    "- **時間**: O(log(min(l, b))) per query → 全体 O(t × log(max constraint))\n",
+    "- **空間**: O(1)"
+   ]
+  }
+ ],
+ "metadata": {
+  "language_info": {
+   "name": "python"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}