{"componentChunkName":"component---src-templates-blog-post-js","path":"/Problem-Solving/2020-01-05-15649번-N과-M-(1)/","result":{"data":{"site":{"siteMetadata":{"title":"Hun's Footsteps 🥷","author":"전여훈","siteUrl":"https://jeonyeohun.netlify.app","comment":{"disqusShortName":"","utterances":"jeonyeohun/jeonyeohun.github.io"},"sponsor":{"buyMeACoffeeId":"jeonyeohun"}}},"markdownRemark":{"id":"c5898ef9-5649-50e9-abbe-79c401382b06","excerpt":"15649번: N과 M (1) 접근 방법: DFS를 통해 해결하는 문제. 백트래킹을 연습하는 단계에 들어왔는데 자료구조때 배웠던 DFS를 다 까먹어서 구글링하면서 다시 공부했다. 전체적인 알고리즘은 깊이를 계속 내려가면서 방문했던 노드를 마킹하고 깊이가 내려갈 때마다 아이템을 넣을 배열 위치를 하나씩 늘려간다. 그리고 배열이 M 길이만큼 채워지면 채워진 값들을 모두 출력하고 리턴한다. 리턴된 이후에는 다시 모든 마킹을 false…","html":"<h3 id=\"15649번-n과-m-1\" style=\"position:relative;\"><a href=\"#15649%EB%B2%88-n%EA%B3%BC-m-1\" aria-label=\"15649번 n과 m 1 permalink\" class=\"anchor before\"><svg aria-hidden=\"true\" focusable=\"false\" height=\"16\" version=\"1.1\" viewBox=\"0 0 16 16\" width=\"16\"><path fill-rule=\"evenodd\" d=\"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"></path></svg></a><a href=\"https://www.acmicpc.net/problem/15649\">15649번: N과 M (1)</a></h3>\n<div class=\"gatsby-highlight\" data-language=\"text\"><pre class=\"language-text\"><code class=\"language-text\">문제\n자연수 N과 M이 주어졌을 때, 아래 조건을 만족하는 길이가 M인 수열을 모두 구하는 프로그램을 작성하시오.\n\n1부터 N까지 자연수 중에서 중복 없이 M개를 고른 수열\n입력\n첫째 줄에 자연수 N과 M이 주어진다. (1 ≤ M ≤ N ≤ 8)\n\n출력\n한 줄에 하나씩 문제의 조건을 만족하는 수열을 출력한다. 중복되는 수열을 여러 번 출력하면 안되며, 각 수열은 공백으로 구분해서 출력해야 한다.\n\n수열은 사전 순으로 증가하는 순서로 출력해야 한다.</code></pre></div>\n<h3 id=\"접근-방법\" style=\"position:relative;\"><a href=\"#%EC%A0%91%EA%B7%BC-%EB%B0%A9%EB%B2%95\" aria-label=\"접근 방법 permalink\" class=\"anchor before\"><svg aria-hidden=\"true\" focusable=\"false\" height=\"16\" version=\"1.1\" viewBox=\"0 0 16 16\" width=\"16\"><path fill-rule=\"evenodd\" d=\"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"></path></svg></a>접근 방법:</h3>\n<p>DFS를 통해 해결하는 문제. 백트래킹을 연습하는 단계에 들어왔는데 자료구조때 배웠던 DFS를 다 까먹어서 구글링하면서 다시 공부했다. 전체적인 알고리즘은 깊이를 계속 내려가면서 방문했던 노드를 마킹하고 깊이가 내려갈 때마다 아이템을 넣을 배열 위치를 하나씩 늘려간다. 그리고 배열이 M 길이만큼 채워지면 채워진 값들을 모두 출력하고 리턴한다. 리턴된 이후에는 다시 모든 마킹을 false로 처리해주어야 다음번 경우의 수에서 값들을 정상적으로 체크할 수 있다.</p>\n<h3 id=\"통과-코드\" style=\"position:relative;\"><a href=\"#%ED%86%B5%EA%B3%BC-%EC%BD%94%EB%93%9C\" aria-label=\"통과 코드 permalink\" class=\"anchor before\"><svg aria-hidden=\"true\" focusable=\"false\" height=\"16\" version=\"1.1\" viewBox=\"0 0 16 16\" width=\"16\"><path fill-rule=\"evenodd\" d=\"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"></path></svg></a>통과 코드:</h3>\n<div class=\"gatsby-highlight\" data-language=\"cpp\"><pre class=\"language-cpp\"><code class=\"language-cpp\"><span class=\"token macro property\"><span class=\"token directive-hash\">#</span><span class=\"token directive keyword\">include</span> <span class=\"token string\">&lt;iostream></span></span>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#</span><span class=\"token directive keyword\">include</span> <span class=\"token string\">&lt;vector></span></span>\n\n<span class=\"token keyword\">using</span> <span class=\"token keyword\">namespace</span> std<span class=\"token punctuation\">;</span>\nvector<span class=\"token operator\">&lt;</span><span class=\"token keyword\">bool</span><span class=\"token operator\">></span> <span class=\"token function\">visited</span><span class=\"token punctuation\">(</span><span class=\"token number\">9</span><span class=\"token punctuation\">,</span> <span class=\"token boolean\">false</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">;</span>\nvector<span class=\"token operator\">&lt;</span><span class=\"token keyword\">int</span><span class=\"token operator\">></span> <span class=\"token function\">numbers</span><span class=\"token punctuation\">(</span><span class=\"token number\">9</span><span class=\"token punctuation\">,</span> <span class=\"token number\">0</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">;</span>\n<span class=\"token keyword\">int</span> N<span class=\"token punctuation\">,</span> M<span class=\"token punctuation\">;</span>\n\n<span class=\"token keyword\">void</span> <span class=\"token function\">DFS</span><span class=\"token punctuation\">(</span><span class=\"token keyword\">int</span> cnt<span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span>\n    <span class=\"token keyword\">if</span> <span class=\"token punctuation\">(</span>cnt <span class=\"token operator\">==</span> M<span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span> <span class=\"token comment\">// 배열에 값이 4개가 쌓이면 출력하고 종료</span>\n        <span class=\"token keyword\">for</span> <span class=\"token punctuation\">(</span><span class=\"token keyword\">int</span> i <span class=\"token operator\">=</span> <span class=\"token number\">0</span> <span class=\"token punctuation\">;</span> i <span class=\"token operator\">&lt;</span> M <span class=\"token punctuation\">;</span> i<span class=\"token operator\">++</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span>\n            cout <span class=\"token operator\">&lt;&lt;</span> numbers<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span> <span class=\"token operator\">&lt;&lt;</span> <span class=\"token string\">\" \"</span><span class=\"token punctuation\">;</span>\n        <span class=\"token punctuation\">}</span>\n        cout <span class=\"token operator\">&lt;&lt;</span> <span class=\"token string\">\"\\n\"</span><span class=\"token punctuation\">;</span>\n        <span class=\"token keyword\">return</span><span class=\"token punctuation\">;</span>\n    <span class=\"token punctuation\">}</span>\n\n    <span class=\"token keyword\">for</span> <span class=\"token punctuation\">(</span><span class=\"token keyword\">int</span> i <span class=\"token operator\">=</span> <span class=\"token number\">1</span> <span class=\"token punctuation\">;</span> i <span class=\"token operator\">&lt;=</span> N <span class=\"token punctuation\">;</span> i<span class=\"token operator\">++</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span> <span class=\"token comment\">// 자기 자신을 제외한 다른 노드들에 방문한 적이 있는지 확인</span>\n        <span class=\"token keyword\">if</span><span class=\"token punctuation\">(</span><span class=\"token operator\">!</span>visited<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span> <span class=\"token comment\">// 처음 방문하는 노드를 만나면</span>\n            visited<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> <span class=\"token boolean\">true</span><span class=\"token punctuation\">;</span> <span class=\"token comment\">// 방문했다고 마킹하고</span>\n            numbers<span class=\"token punctuation\">[</span>cnt<span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> i<span class=\"token punctuation\">;</span> <span class=\"token comment\">// 배열 0번째의 값 넣기</span>\n            <span class=\"token function\">DFS</span><span class=\"token punctuation\">(</span>cnt<span class=\"token operator\">+</span><span class=\"token number\">1</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">;</span> <span class=\"token comment\">// 다음 배열에 넣을 값 찾기 재귀호출</span>\n            visited<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> <span class=\"token boolean\">false</span><span class=\"token punctuation\">;</span> <span class=\"token comment\">// 여기에 왔다는건 cnt+1번째 배열에 값이 들어있는채로 리턴된거니까 다시 false로 만들어줘야 다음번 수열을 찾을 때 사용할 수 있다.</span>\n        <span class=\"token punctuation\">}</span>\n    <span class=\"token punctuation\">}</span>\n<span class=\"token punctuation\">}</span>\n\n<span class=\"token keyword\">int</span> <span class=\"token function\">main</span> <span class=\"token punctuation\">(</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span>\n    ios_base<span class=\"token operator\">::</span><span class=\"token function\">sync_with_stdio</span><span class=\"token punctuation\">(</span><span class=\"token boolean\">false</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">;</span>\n    cin<span class=\"token punctuation\">.</span><span class=\"token function\">tie</span><span class=\"token punctuation\">(</span><span class=\"token constant\">NULL</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">;</span>\n\n    cin <span class=\"token operator\">>></span> N <span class=\"token operator\">>></span> M<span class=\"token punctuation\">;</span>\n    <span class=\"token function\">DFS</span><span class=\"token punctuation\">(</span><span class=\"token number\">0</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">;</span>\n\n    <span class=\"token keyword\">return</span> <span class=\"token number\">0</span><span class=\"token punctuation\">;</span>\n<span class=\"token punctuation\">}</span>\n\n<span class=\"token punctuation\">}</span></code></pre></div>","frontmatter":{"title":"[백준 알고리즘] 15649번: N과 M (1)","date":"May 05, 2020"}}},"pageContext":{"slug":"/Problem-Solving/2020-01-05-15649번-N과-M-(1)/","previous":{"fields":{"slug":"/Problem-Solving/2020-01-05-15650번-N과-M-(2)/"},"frontmatter":{"title":"[백준 알고리즘] 15650번: N과 M (2)","category":"Problem-Solving","draft":false}},"next":{"fields":{"slug":"/Problem-Solving/2020-01-05-11651번-좌표-정렬하기-2/"},"frontmatter":{"title":"[백준 알고리즘] 11651번: 좌표 정렬하기 2","category":"Problem-Solving","draft":false}}}},"staticQueryHashes":["2486386679","3128451518"]}