feat: マージソート、ヒープ

xhiroga · May 16, 2024 · 1664d0d · 1664d0d
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diff --git a/computer-science/data-structures-algorithms/_src/algorithm-and-datastructure/ALDS1_5_B.ipynb b/computer-science/data-structures-algorithms/_src/algorithm-and-datastructure/ALDS1_5_B.ipynb
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+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# マージソート\n"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "クラス内で男女別の成績順のリストを、男女問わずの成績順のリストに合体するようなイメージ。\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 33,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from logging import getLogger, StreamHandler, DEBUG\n",
+    "\n",
+    "logger = getLogger(__name__)\n",
+    "handler = StreamHandler()\n",
+    "handler.setLevel(DEBUG)\n",
+    "logger.setLevel(DEBUG)\n",
+    "logger.addHandler(handler)\n",
+    "logger.propagate = False\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 34,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def merge(left_list: list[int], right_list: list[int]):\n",
+    "    logger.debug(f\"{left_list=}, {right_list=}\")\n",
+    "    merged = []\n",
+    "    left = left_list.pop(0)\n",
+    "    right = right_list.pop(0)\n",
+    "\n",
+    "    while True:\n",
+    "        if left < right:\n",
+    "            merged.append(left)\n",
+    "            logger.debug(f\"{merged=}, {left=}, {left_list=}, {right=}, {right_list=}\")\n",
+    "            try:\n",
+    "                left = left_list.pop(0)\n",
+    "            except IndexError as _:\n",
+    "                return merged + [right] + right_list\n",
+    "        else:\n",
+    "            merged.append(right)\n",
+    "            logger.debug(f\"{merged=}, {left=}, {left_list=}, {right=}, {right_list=}\")\n",
+    "            try:\n",
+    "                right = right_list.pop(0)\n",
+    "            except IndentationError as _:\n",
+    "                return merged + [left] + left_list\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 35,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "left_list=[1, 2, 5], right_list=[3, 4, 6]\n",
+      "left_list=[1, 2, 5], right_list=[3, 4, 6]\n",
+      "merged=[1], left=1, left_list=[2, 5], right=3, right_list=[4, 6]\n",
+      "merged=[1], left=1, left_list=[2, 5], right=3, right_list=[4, 6]\n",
+      "merged=[1, 2], left=2, left_list=[5], right=3, right_list=[4, 6]\n",
+      "merged=[1, 2], left=2, left_list=[5], right=3, right_list=[4, 6]\n",
+      "merged=[1, 2, 3], left=5, left_list=[], right=3, right_list=[4, 6]\n",
+      "merged=[1, 2, 3], left=5, left_list=[], right=3, right_list=[4, 6]\n",
+      "merged=[1, 2, 3, 4], left=5, left_list=[], right=4, right_list=[6]\n",
+      "merged=[1, 2, 3, 4], left=5, left_list=[], right=4, right_list=[6]\n",
+      "merged=[1, 2, 3, 4, 5], left=5, left_list=[], right=6, right_list=[]\n",
+      "merged=[1, 2, 3, 4, 5], left=5, left_list=[], right=6, right_list=[]\n"
+     ]
+    }
+   ],
+   "source": [
+    "expected = [1, 2, 3, 4, 5, 6]\n",
+    "actual = merge([1, 2, 5], [3, 4, 6])\n",
+    "assert expected == actual\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 40,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def merge_sort(nums: list[int]):\n",
+    "    logger.debug(f\"{nums=}\")\n",
+    "    if len(nums) == 1:\n",
+    "        return nums\n",
+    "\n",
+    "    mid = len(nums) // 2\n",
+    "    left_list = merge_sort(nums[:mid])\n",
+    "    right_list = merge_sort(nums[mid:])\n",
+    "    logger.debug(f\"{left_list=}, {right_list=}\")\n",
+    "    return merge(left_list, right_list)\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 42,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "nums=[1, 2, 5, 3, 4, 6]\n",
+      "nums=[1, 2, 5, 3, 4, 6]\n",
+      "nums=[1, 2, 5]\n",
+      "nums=[1, 2, 5]\n",
+      "nums=[1]\n",
+      "nums=[1]\n",
+      "nums=[2, 5]\n",
+      "nums=[2, 5]\n",
+      "nums=[2]\n",
+      "nums=[2]\n",
+      "nums=[5]\n",
+      "nums=[5]\n",
+      "left_list=[2], right_list=[5]\n",
+      "left_list=[2], right_list=[5]\n",
+      "left_list=[2], right_list=[5]\n",
+      "left_list=[2], right_list=[5]\n",
+      "merged=[2], left=2, left_list=[], right=5, right_list=[]\n",
+      "merged=[2], left=2, left_list=[], right=5, right_list=[]\n",
+      "left_list=[1], right_list=[2, 5]\n",
+      "left_list=[1], right_list=[2, 5]\n",
+      "left_list=[1], right_list=[2, 5]\n",
+      "left_list=[1], right_list=[2, 5]\n",
+      "merged=[1], left=1, left_list=[], right=2, right_list=[5]\n",
+      "merged=[1], left=1, left_list=[], right=2, right_list=[5]\n",
+      "nums=[3, 4, 6]\n",
+      "nums=[3, 4, 6]\n",
+      "nums=[3]\n",
+      "nums=[3]\n",
+      "nums=[4, 6]\n",
+      "nums=[4, 6]\n",
+      "nums=[4]\n",
+      "nums=[4]\n",
+      "nums=[6]\n",
+      "nums=[6]\n",
+      "left_list=[4], right_list=[6]\n",
+      "left_list=[4], right_list=[6]\n",
+      "left_list=[4], right_list=[6]\n",
+      "left_list=[4], right_list=[6]\n",
+      "merged=[4], left=4, left_list=[], right=6, right_list=[]\n",
+      "merged=[4], left=4, left_list=[], right=6, right_list=[]\n",
+      "left_list=[3], right_list=[4, 6]\n",
+      "left_list=[3], right_list=[4, 6]\n",
+      "left_list=[3], right_list=[4, 6]\n",
+      "left_list=[3], right_list=[4, 6]\n",
+      "merged=[3], left=3, left_list=[], right=4, right_list=[6]\n",
+      "merged=[3], left=3, left_list=[], right=4, right_list=[6]\n",
+      "left_list=[1, 2, 5], right_list=[3, 4, 6]\n",
+      "left_list=[1, 2, 5], right_list=[3, 4, 6]\n",
+      "left_list=[1, 2, 5], right_list=[3, 4, 6]\n",
+      "left_list=[1, 2, 5], right_list=[3, 4, 6]\n",
+      "merged=[1], left=1, left_list=[2, 5], right=3, right_list=[4, 6]\n",
+      "merged=[1], left=1, left_list=[2, 5], right=3, right_list=[4, 6]\n",
+      "merged=[1, 2], left=2, left_list=[5], right=3, right_list=[4, 6]\n",
+      "merged=[1, 2], left=2, left_list=[5], right=3, right_list=[4, 6]\n",
+      "merged=[1, 2, 3], left=5, left_list=[], right=3, right_list=[4, 6]\n",
+      "merged=[1, 2, 3], left=5, left_list=[], right=3, right_list=[4, 6]\n",
+      "merged=[1, 2, 3, 4], left=5, left_list=[], right=4, right_list=[6]\n",
+      "merged=[1, 2, 3, 4], left=5, left_list=[], right=4, right_list=[6]\n",
+      "merged=[1, 2, 3, 4, 5], left=5, left_list=[], right=6, right_list=[]\n",
+      "merged=[1, 2, 3, 4, 5], left=5, left_list=[], right=6, right_list=[]\n"
+     ]
+    }
+   ],
+   "source": [
+    "expected = [1, 2, 3, 4, 5, 6]\n",
+    "actual = merge_sort([1, 2, 5, 3, 4, 6])\n",
+    "assert expected == actual\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "til_machine_learning_py312",
+   "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": "3.12.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}