{"componentChunkName":"component---src-templates-blog-post-js","path":"/Problem-Solving/2021-03-12-1987번-알파벳/","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":"5a3e6d84-b336-5e7e-bd5d-cbed5b82596c","excerpt":"https://www.acmicpc.net/problem/1987 문제 문제 세로 R칸, 가로 C칸으로 된 표 모양의 보드가 있다. 보드의 각 칸에는 대문자 알파벳이 하나씩 적혀 있고, 좌측 상단 칸 (1행…","html":"<p><a href=\"https://www.acmicpc.net/problem/1987\">https://www.acmicpc.net/problem/1987</a></p>\n<h2 id=\"문제\" style=\"position:relative;\"><a href=\"#%EB%AC%B8%EC%A0%9C\" aria-label=\"문제 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>문제</h2>\n<p><strong>문제</strong><br></p>\n<p>세로 R칸, 가로 C칸으로 된 표 모양의 보드가 있다. 보드의 각 칸에는 대문자 알파벳이 하나씩 적혀 있고, 좌측 상단 칸 (1행 1열) 에는 말이 놓여 있다.</p>\n<p>말은 상하좌우로 인접한 네 칸 중의 한 칸으로 이동할 수 있는데, 새로 이동한 칸에 적혀 있는 알파벳은 지금까지 지나온 모든 칸에 적혀 있는 알파벳과는 달라야 한다. 즉, 같은 알파벳이 적힌 칸을 두 번 지날 수 없다.</p>\n<p>좌측 상단에서 시작해서, 말이 최대한 몇 칸을 지날 수 있는지를 구하는 프로그램을 작성하시오. 말이 지나는 칸은 좌측 상단의 칸도 포함된다.</p>\n<p><strong>입력</strong><br></p>\n<p>첫째 줄에 R과 C가 빈칸을 사이에 두고 주어진다. (1 ≤ R,C ≤ 20) 둘째 줄부터 R개의 줄에 걸쳐서 보드에 적혀 있는 C개의 대문자 알파벳들이 빈칸 없이 주어진다.</p>\n<p><strong>출력</strong><br></p>\n<p>첫째 줄에 말이 지날 수 있는 최대의 칸 수를 출력한다.</p>\n<h2 id=\"풀이\" style=\"position:relative;\"><a href=\"#%ED%92%80%EC%9D%B4\" aria-label=\"풀이 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>풀이</h2>\n<p>문제에서 주어진 조건대로 4방향을 확인하면서 갈 수 있는 데까지 다 가보는 문제였다. DFS를 이용해서 이동횟수를 확인했는데, 이미 경로에서 사용했던 알파벳인지 확인하기 위해서 알파벳을 저장할 수 있는 배열을 하나 만들고 방문할 때마다. 이미 사용한 알파벳으로 체크해주었다. 알파벳은 해당 문자에 65를 빼면 0에서 부터 인덱싱이 가능하기 때문에 매번 65를 빼서 길이 26의 배열로 해결할 수 있도록 했다.</p>\n<p>이 문제는 정점 방문여부를 배열이 따로 필요가 없었는데, 이미 방문했던 정점은 항상 사용한 알파벳으로 체크가 되기 때문에 사용한 알파벳을 확인하는 것으로 방문정점의 체크가 가능하다.</p>\n<h2 id=\"코드\" style=\"position:relative;\"><a href=\"#%EC%BD%94%EB%93%9C\" aria-label=\"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>코드</h2>\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;algorithm></span></span>\n\n<span class=\"token keyword\">using</span> <span class=\"token keyword\">namespace</span> std<span class=\"token punctuation\">;</span>\n\n<span class=\"token keyword\">const</span> <span class=\"token keyword\">int</span> MAX <span class=\"token operator\">=</span> <span class=\"token number\">21</span><span class=\"token punctuation\">;</span>\n\n<span class=\"token keyword\">int</span> R<span class=\"token punctuation\">,</span> C<span class=\"token punctuation\">;</span>\n<span class=\"token keyword\">bool</span> alphaUsed<span class=\"token punctuation\">[</span><span class=\"token number\">26</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">;</span>\n<span class=\"token keyword\">char</span> board<span class=\"token punctuation\">[</span>MAX<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span>MAX<span class=\"token punctuation\">]</span><span class=\"token punctuation\">;</span>\n\n<span class=\"token keyword\">int</span> maxMove <span class=\"token operator\">=</span> <span class=\"token number\">0</span><span class=\"token punctuation\">;</span>\n\n<span class=\"token keyword\">bool</span> <span class=\"token function\">isMovePossible</span> <span class=\"token punctuation\">(</span><span class=\"token keyword\">int</span> r<span class=\"token punctuation\">,</span> <span class=\"token keyword\">int</span> c<span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span>\n    <span class=\"token keyword\">return</span> <span class=\"token punctuation\">(</span>r <span class=\"token operator\">>=</span> <span class=\"token number\">0</span> <span class=\"token operator\">&amp;&amp;</span> r <span class=\"token operator\">&lt;</span> R<span class=\"token punctuation\">)</span> <span class=\"token operator\">&amp;&amp;</span> <span class=\"token punctuation\">(</span>c <span class=\"token operator\">>=</span> <span class=\"token number\">0</span> <span class=\"token operator\">&amp;&amp;</span> c <span class=\"token operator\">&lt;</span> C<span class=\"token punctuation\">)</span><span class=\"token punctuation\">;</span>\n<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> row<span class=\"token punctuation\">,</span> <span class=\"token keyword\">int</span> col<span class=\"token punctuation\">,</span> <span class=\"token keyword\">int</span> move<span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span>\n    alphaUsed<span class=\"token punctuation\">[</span>board<span class=\"token punctuation\">[</span>row<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span>col<span class=\"token punctuation\">]</span> <span class=\"token operator\">-</span> <span class=\"token number\">65</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> <span class=\"token boolean\">true</span><span class=\"token punctuation\">;</span>\n\n    <span class=\"token keyword\">int</span> rowDir <span class=\"token punctuation\">[</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> <span class=\"token punctuation\">{</span><span class=\"token number\">1</span><span class=\"token punctuation\">,</span> <span class=\"token operator\">-</span><span class=\"token number\">1</span><span class=\"token punctuation\">,</span> <span class=\"token number\">0</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> colDir <span class=\"token punctuation\">[</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> <span class=\"token punctuation\">{</span><span class=\"token number\">0</span><span class=\"token punctuation\">,</span> <span class=\"token number\">0</span><span class=\"token punctuation\">,</span> <span class=\"token operator\">-</span><span class=\"token number\">1</span><span class=\"token punctuation\">,</span> <span class=\"token number\">1</span><span class=\"token punctuation\">}</span><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\">0</span> <span class=\"token punctuation\">;</span> i <span class=\"token operator\">&lt;</span> <span class=\"token number\">4</span> <span class=\"token punctuation\">;</span> i<span class=\"token operator\">++</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span>\n        <span class=\"token keyword\">int</span> nextRow <span class=\"token operator\">=</span> row <span class=\"token operator\">+</span> rowDir<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">;</span>\n        <span class=\"token keyword\">int</span> nextCol <span class=\"token operator\">=</span> col <span class=\"token operator\">+</span> colDir<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">;</span>\n        <span class=\"token keyword\">if</span><span class=\"token punctuation\">(</span><span class=\"token function\">isMovePossible</span><span class=\"token punctuation\">(</span>nextRow<span class=\"token punctuation\">,</span> nextCol<span class=\"token punctuation\">)</span> <span class=\"token operator\">&amp;&amp;</span> <span class=\"token operator\">!</span>alphaUsed<span class=\"token punctuation\">[</span>board<span class=\"token punctuation\">[</span>nextRow<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span>nextCol<span class=\"token punctuation\">]</span> <span class=\"token operator\">-</span> <span class=\"token number\">65</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span>\n                <span class=\"token function\">dfs</span><span class=\"token punctuation\">(</span>nextRow<span class=\"token punctuation\">,</span> nextCol<span class=\"token punctuation\">,</span> move <span class=\"token operator\">+</span> <span class=\"token number\">1</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">;</span>\n        <span class=\"token punctuation\">}</span>\n    <span class=\"token punctuation\">}</span>\n    alphaUsed<span class=\"token punctuation\">[</span>board<span class=\"token punctuation\">[</span>row<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span>col<span class=\"token punctuation\">]</span> <span class=\"token operator\">-</span> <span class=\"token number\">65</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> <span class=\"token boolean\">false</span><span class=\"token punctuation\">;</span>\n    maxMove <span class=\"token operator\">=</span> <span class=\"token function\">max</span><span class=\"token punctuation\">(</span>maxMove<span class=\"token punctuation\">,</span> move<span class=\"token punctuation\">)</span><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\n    ios_base<span class=\"token operator\">::</span><span class=\"token function\">sync_with_stdio</span><span class=\"token punctuation\">(</span><span class=\"token number\">0</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> R <span class=\"token operator\">>></span> C<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\">0</span> <span class=\"token punctuation\">;</span> i <span class=\"token operator\">&lt;</span> R <span class=\"token punctuation\">;</span> i<span class=\"token operator\">++</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span>\n        <span class=\"token keyword\">for</span> <span class=\"token punctuation\">(</span><span class=\"token keyword\">int</span> j <span class=\"token operator\">=</span> <span class=\"token number\">0</span> <span class=\"token punctuation\">;</span> j <span class=\"token operator\">&lt;</span> C <span class=\"token punctuation\">;</span> j<span class=\"token operator\">++</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span>\n            cin <span class=\"token operator\">>></span> board<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span>j<span class=\"token punctuation\">]</span><span class=\"token punctuation\">;</span>\n        <span class=\"token punctuation\">}</span>\n    <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 number\">0</span><span class=\"token punctuation\">,</span> <span class=\"token number\">1</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">;</span>\n\n    cout <span class=\"token operator\">&lt;&lt;</span> maxMove<span class=\"token punctuation\">;</span>\n<span class=\"token punctuation\">}</span></code></pre></div>","frontmatter":{"title":"[백준 알고리즘] 1987번: 알파벳","date":"March 12, 2021"}}},"pageContext":{"slug":"/Problem-Solving/2021-03-12-1987번-알파벳/","previous":{"fields":{"slug":"/Problem-Solving/2021-03-11-2110번-공유기설치/"},"frontmatter":{"title":"[백준 알고리즘] 2110번: 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