4주차 과제 _ 김민혜

minhae/4주차 과제_김민혜.ipynb

@@ -0,0 +1,278 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "id": "e21ff13f",
+   "metadata": {},
+   "source": [
+    "p.137 문제 23번. 연결 요소의 개수 구하기"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "60340567",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "6 5\n",
+      "1 2\n",
+      "2 5\n",
+      "5 1\n",
+      "3 4\n",
+      "4 6\n"
+     ]
+    },
+    {
+     "ename": "IndexError",
+     "evalue": "list index out of range",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
+      "\u001b[0;31mIndexError\u001b[0m                                Traceback (most recent call last)",
+      "Input \u001b[0;32mIn [4]\u001b[0m, in \u001b[0;36m<cell line: 18>\u001b[0;34m()\u001b[0m\n\u001b[1;32m     16\u001b[0m count \u001b[38;5;241m=\u001b[39m \u001b[38;5;241m0\u001b[39m\n\u001b[1;32m     18\u001b[0m \u001b[38;5;28;01mfor\u001b[39;00m i \u001b[38;5;129;01min\u001b[39;00m \u001b[38;5;28mrange\u001b[39m(\u001b[38;5;241m1\u001b[39m \u001b[38;5;241m+\u001b[39m N\u001b[38;5;241m+\u001b[39m\u001b[38;5;241m1\u001b[39m):\n\u001b[0;32m---> 19\u001b[0m     \u001b[38;5;28;01mif\u001b[39;00m \u001b[38;5;129;01mnot\u001b[39;00m \u001b[43mvisit\u001b[49m\u001b[43m[\u001b[49m\u001b[43mi\u001b[49m\u001b[43m]\u001b[49m:\n\u001b[1;32m     20\u001b[0m         count \u001b[38;5;241m+\u001b[39m\u001b[38;5;241m=\u001b[39m \u001b[38;5;241m1\u001b[39m\n\u001b[1;32m     21\u001b[0m         DFS(i)\n",
+      "\u001b[0;31mIndexError\u001b[0m: list index out of range"
+     ]
+    }
+   ],
+   "source": [
+    "N, M = map(int, input().split())\n",
+    "A = [[] for i in range(N + 1)]\n",
+    "visit = [False] * (N+1)\n",
+    "\n",
+    "def DFS(x):\n",
+    "    visit[x] = True\n",
+    "    for i in A[x]:\n",
+    "        if not visit[i]:\n",
+    "            DFS(i)\n",
+    "            \n",
+    "for i in range(M):\n",
+    "    f,w = map(int, input().split())\n",
+    "    A[f].append(w)\n",
+    "    A[w].append(f)\n",
+    "    \n",
+    "count = 0\n",
+    "\n",
+    "for i in range(1 + N+1):\n",
+    "    if not visit[i]:\n",
+    "        count += 1\n",
+    "        DFS(i)\n",
+    "        \n",
+    "print(count)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "c732f09f",
+   "metadata": {},
+   "source": [
+    "p.152 문제 26번. DFS와 BFS 프로그램"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "id": "0210d6fb",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "5 5 3\n",
+      "5 4\n",
+      "5 2\n",
+      "1 2\n",
+      "3 4\n",
+      "3 1\n",
+      "331425"
+     ]
+    }
+   ],
+   "source": [
+    "from collections import deque\n",
+    "n, m, s = map(int, input().split())\n",
+    "A = [[] for i in range(n+1)]\n",
+    "\n",
+    "for k in range(M):\n",
+    "    f,w = map(int, input().split())\n",
+    "    A[f].append(w)\n",
+    "    A[w].append(f)\n",
+    "    \n",
+    "for u in range(n+1):\n",
+    "    A[u].sort()\n",
+    "    \n",
+    "def DFS(x):\n",
+    "    print(x, end='')\n",
+    "    visit[x] = True\n",
+    "    for i in A[x]:\n",
+    "        if not visit[x]:\n",
+    "            DFS(i)\n",
+    "            \n",
+    "visit = [False] * (n+1)\n",
+    "DFS(s)\n",
+    "\n",
+    "def BFS(x):\n",
+    "    queue = deque()\n",
+    "    queue.append(x)\n",
+    "    visit[x] = True\n",
+    "    while queue:\n",
+    "        now_Node = queue.popleft()\n",
+    "        print(now_Node, end = '')\n",
+    "        for i in A[now_Node]:\n",
+    "            if not visit[i]:\n",
+    "                visit[i] = True\n",
+    "                queue.append(i)\n",
+    "                \n",
+    "visit = [False] * (n+1)\n",
+    "BFS(s)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "fd0f209c",
+   "metadata": {},
+   "source": [
+    "p.169 문제29번. 원하는 정수 찾기"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "id": "2116d5cc",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "5\n",
+      "4 1 5 2 3\n",
+      "5 \n",
+      "1 3 7 9 5\n",
+      "1\n",
+      "1\n",
+      "0\n",
+      "0\n",
+      "1\n"
+     ]
+    }
+   ],
+   "source": [
+    "N = int(input())\n",
+    "A = list(map(int, input().split()))\n",
+    "A.sort() # 이진탐색은 오름차순으로 정렬된 리스트를 활용해야 함으로\n",
+    "M = int(input())\n",
+    "target = list(map(int, input().split()))\n",
+    "\n",
+    "for i in range(M):\n",
+    "    flag = False\n",
+    "    t = target[i]\n",
+    "    \n",
+    "    start = 0\n",
+    "    end = len(A)-1\n",
+    "    while start <= end:\n",
+    "        mid = int((start + end) / 2)\n",
+    "        mid2 = A[mid]\n",
+    "        if mid2 > t:\n",
+    "            end = mid - 1\n",
+    "        elif mid2 < t:\n",
+    "            start = mid + 1\n",
+    "        else:\n",
+    "            flag = True\n",
+    "            break\n",
+    "            \n",
+    "    if flag:\n",
+    "        print(1)\n",
+    "    else:\n",
+    "        print(0)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "35f128e5",
+   "metadata": {},
+   "source": [
+    "p.183 문제32번. 동전 개수의 최솟값 구하기"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "id": "849a6f70",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "10 4200\n",
+      "1\n",
+      "5\n",
+      "10\n",
+      "50\n",
+      "100\n",
+      "500\n",
+      "1000\n",
+      "5000\n",
+      "10000\n",
+      "50000\n",
+      "6\n"
+     ]
+    }
+   ],
+   "source": [
+    "n,k = map(int, input().split())\n",
+    "count = 0\n",
+    "money = []\n",
+    "\n",
+    "for i in range(n):\n",
+    "    a = int(input())\n",
+    "    money.append(a)\n",
+    "    \n",
+    "\n",
+    "\n",
+    "money = list(reversed(money))\n",
+    "\n",
+    "for m in money:\n",
+    "    b = k//m\n",
+    "    count += b\n",
+    "    k -= m * b\n",
+    "    \n",
+    "print(count)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "42252371",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3 (ipykernel)",
+   "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": "3.10.6"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}

minhae/4주차 과제_김민혜

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+DFS와 BFS는 확실히 어려웠습니다! 그래서 책 코드를 많이 참고하게 된 것 같아요,,
+반면 binary search와 그리디는 상대적으로 쉽게 느껴졌어요. 
+DFS, BFS 문제 많이 풀어야 할 것 같습니다 🥲