{"componentChunkName":"component---src-templates-post-template-js","path":"/posts/algorithm-problem/programmers/programmers-42861","result":{"data":{"markdownRemark":{"id":"f3841e34-1229-500b-94ac-a8c35f0a9b08","html":"<h3 id=\"문제주소\" style=\"position:relative;\"><a href=\"#%EB%AC%B8%EC%A0%9C%EC%A3%BC%EC%86%8C\" aria-label=\"문제주소 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>문제주소</h3>\n<blockquote>\n<p><a href=\"https://programmers.co.kr/learn/courses/30/lessons/42861\" target=\"_blank\" rel=\"nofollow noopener noreferrer\">https://programmers.co.kr/learn/courses/30/lessons/42861</a></p>\n</blockquote>\n<h3 id=\"문제접근-방식\" style=\"position:relative;\"><a href=\"#%EB%AC%B8%EC%A0%9C%EC%A0%91%EA%B7%BC-%EB%B0%A9%EC%8B%9D\" aria-label=\"문제접근 방식 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>문제접근 방식</h3>\n<p>도시 연결 + 그리디 👉 MST 문제 👉 Kruskal</p>\n<ol>\n<li>입력된 edge를 weight를 기준으로 오름차순 정렬</li>\n<li>두개의 배열을 초기화 한다.</li>\n<li>visited : node의 방문여부 기록, 기록되는 값은 노드가 속하는 그룹, 0으로 초기화</li>\n<li>answer : 선택된 edge의 weight를 기록, 빈 배열로 초기화</li>\n<li>\n<p>edge를 순회하면 아래의 조건에 따라 동작하면 배열의 값을 변경한다.</p>\n<ul>\n<li>\n<p>현재 선택된 edge에 연결된 두 node n1, n2에 대하여</p>\n<ul>\n<li>두 노드 다 방문 전(<code class=\"language-text\">visited[n1] == 0 &amp;&amp; visited[n2] == 0</code>)이라면, 새로운 그룹을 추가하고 visited의 값을 그룹으로 할당한다. answer에 현재 edge의 weight를 추가한다.</li>\n<li>두 노드 중 하나의 노드에 방문을 했었다(<code class=\"language-text\">visited[n1] == 0 &amp;&amp; visited[n2] > 0</code>, <code class=\"language-text\">visited[n1] > 0 &amp;&amp; visited[n2] == 0</code>)면, 방문 전 노드의 visited 값을 방문한 노드의 그룹 값으로 할당한다. answer에 현재 edge의 weight를 추가한다.</li>\n<li>두 노드를 모두 방문했었는데 서로 같은 그룹(<code class=\"language-text\">visited[n1] == visited[n2]</code>)이라면, 아무 동작도 하지 않는다.</li>\n<li>두 노드를 모두 방문했었는데 서로 다른 그룹(<code class=\"language-text\">visited[n1] != visited[n2] &amp;&amp; visited[n1] > 0 &amp;&amp; visited[n2] > 0</code>)이라면, n2의 그룹을 n로 병합한다. answer에 현재 node의 weight를 추가한다.</li>\n</ul>\n</li>\n</ul>\n</li>\n<li>answer의 길이가 n-1에 도달하면 순회를 종료한다.</li>\n<li>answer의 합을 반환한다.</li>\n</ol>\n<h4 id=\"입출력-예\" style=\"position:relative;\"><a href=\"#%EC%9E%85%EC%B6%9C%EB%A0%A5-%EC%98%88\" aria-label=\"입출력 예 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>입출력 예</h4>\n<p>n=4, costs=[[0,1,1],[0,2,2],[1,2,5],[1,3,1],[2,3,8]], return=4</p>\n<p><span\n      class=\"gatsby-resp-image-wrapper\"\n      style=\"position: relative; display: block; margin-left: auto; margin-right: auto; max-width: 366px; \"\n    >\n      <a\n    class=\"gatsby-resp-image-link\"\n    href=\"/static/15282355b2340215eadebb4ce18d8edc/8b153/42861.png\"\n    style=\"display: block\"\n    target=\"_blank\"\n    rel=\"noopener\"\n  >\n    <span\n    class=\"gatsby-resp-image-background-image\"\n    style=\"padding-bottom: 42.91666666666667%; position: relative; bottom: 0; left: 0; background-image: url('data:image/png;base64,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'); background-size: cover; display: block;\"\n  ></span>\n  <picture>\n          <source\n              srcset=\"/static/15282355b2340215eadebb4ce18d8edc/8ac56/42861.webp 240w,\n/static/15282355b2340215eadebb4ce18d8edc/4146f/42861.webp 366w\"\n              sizes=\"(max-width: 366px) 100vw, 366px\"\n              type=\"image/webp\"\n            />\n          <source\n            srcset=\"/static/15282355b2340215eadebb4ce18d8edc/8ff5a/42861.png 240w,\n/static/15282355b2340215eadebb4ce18d8edc/8b153/42861.png 366w\"\n            sizes=\"(max-width: 366px) 100vw, 366px\"\n            type=\"image/png\"\n          />\n          <img\n            class=\"gatsby-resp-image-image\"\n            src=\"/static/15282355b2340215eadebb4ce18d8edc/8b153/42861.png\"\n            alt=\"42861\"\n            title=\"42861\"\n            loading=\"lazy\"\n            style=\"width:100%;height:100%;margin:0;vertical-align:middle;position:absolute;top:0;left:0;\"\n          />\n        </picture>\n  </a>\n    </span></p>\n<h3 id=\"solution\" style=\"position:relative;\"><a href=\"#solution\" aria-label=\"solution 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>Solution</h3>\n<h3 id=\"python\" style=\"position:relative;\"><a href=\"#python\" aria-label=\"python 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>Python</h3>\n<div class=\"gatsby-highlight\" data-language=\"python\"><pre class=\"language-python\"><code class=\"language-python\"><span class=\"token keyword\">import</span> numpy <span class=\"token keyword\">as</span> np\n\n<span class=\"token keyword\">def</span> <span class=\"token function\">solution</span><span class=\"token punctuation\">(</span>n<span class=\"token punctuation\">,</span> costs<span class=\"token punctuation\">)</span><span class=\"token punctuation\">:</span>\n    visited <span class=\"token operator\">=</span> np<span class=\"token punctuation\">.</span>zeros<span class=\"token punctuation\">(</span>n<span class=\"token punctuation\">,</span> dtype<span class=\"token operator\">=</span><span class=\"token builtin\">int</span><span class=\"token punctuation\">)</span> <span class=\"token comment\"># cycle 체크를 위한 그룹기입</span>\n    answer <span class=\"token operator\">=</span> <span class=\"token punctuation\">[</span><span class=\"token punctuation\">]</span> <span class=\"token comment\"># 선택된 간선의 weight</span>\n    g <span class=\"token operator\">=</span> <span class=\"token number\">0</span> <span class=\"token comment\"># 그룹번호</span>\n\n    costs_sorted <span class=\"token operator\">=</span>  <span class=\"token builtin\">sorted</span><span class=\"token punctuation\">(</span>costs<span class=\"token punctuation\">,</span> key<span class=\"token operator\">=</span><span class=\"token keyword\">lambda</span> x<span class=\"token punctuation\">:</span> x<span class=\"token punctuation\">[</span><span class=\"token number\">2</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">)</span>\n\n    <span class=\"token keyword\">for</span> s<span class=\"token punctuation\">,</span> e<span class=\"token punctuation\">,</span> c <span class=\"token keyword\">in</span> costs_sorted<span class=\"token punctuation\">:</span>\n        <span class=\"token keyword\">if</span> visited<span class=\"token punctuation\">[</span>s<span class=\"token punctuation\">]</span> <span class=\"token operator\">==</span> <span class=\"token number\">0</span> <span class=\"token keyword\">and</span> visited<span class=\"token punctuation\">[</span>e<span class=\"token punctuation\">]</span> <span class=\"token operator\">==</span> <span class=\"token number\">0</span><span class=\"token punctuation\">:</span> <span class=\"token comment\"># 둘다 방문 X</span>\n            <span class=\"token comment\"># 그룹 추가</span>\n            g <span class=\"token operator\">+=</span> <span class=\"token number\">1</span>\n            visited<span class=\"token punctuation\">[</span>s<span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> g\n            visited<span class=\"token punctuation\">[</span>e<span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> g\n        <span class=\"token keyword\">elif</span> visited<span class=\"token punctuation\">[</span>s<span class=\"token punctuation\">]</span> <span class=\"token operator\">==</span> visited<span class=\"token punctuation\">[</span>e<span class=\"token punctuation\">]</span><span class=\"token punctuation\">:</span> <span class=\"token comment\"># 같은 그룹</span>\n            <span class=\"token keyword\">continue</span>\n        <span class=\"token keyword\">elif</span> visited<span class=\"token punctuation\">[</span>s<span class=\"token punctuation\">]</span> <span class=\"token operator\">></span> <span class=\"token number\">0</span> <span class=\"token keyword\">and</span> visited<span class=\"token punctuation\">[</span>e<span class=\"token punctuation\">]</span> <span class=\"token operator\">==</span> <span class=\"token number\">0</span><span class=\"token punctuation\">:</span> <span class=\"token comment\"># 첫번째만 방문</span>\n            <span class=\"token comment\"># 두번쨰가 첫번째 그룹으로 삽입</span>\n            visited<span class=\"token punctuation\">[</span>e<span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> visited<span class=\"token punctuation\">[</span>s<span class=\"token punctuation\">]</span>\n        <span class=\"token keyword\">elif</span> visited<span class=\"token punctuation\">[</span>s<span class=\"token punctuation\">]</span> <span class=\"token operator\">==</span> <span class=\"token number\">0</span> <span class=\"token keyword\">and</span> visited<span class=\"token punctuation\">[</span>e<span class=\"token punctuation\">]</span> <span class=\"token operator\">></span> <span class=\"token number\">0</span><span class=\"token punctuation\">:</span> <span class=\"token comment\"># 두번째만 방문</span>\n            visited<span class=\"token punctuation\">[</span>s<span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> visited<span class=\"token punctuation\">[</span>e<span class=\"token punctuation\">]</span>\n        <span class=\"token keyword\">else</span><span class=\"token punctuation\">:</span> <span class=\"token comment\"># 서로 다른 그룹</span>\n            <span class=\"token comment\"># 두번째가 속한 그룹을 첫번째가 속한 그룹으로 병합</span>\n            visited<span class=\"token punctuation\">[</span>visited <span class=\"token operator\">==</span> visited<span class=\"token punctuation\">[</span>e<span class=\"token punctuation\">]</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> visited<span class=\"token punctuation\">[</span>s<span class=\"token punctuation\">]</span>\n\n        answer<span class=\"token punctuation\">.</span>append<span class=\"token punctuation\">(</span>c<span class=\"token punctuation\">)</span>\n        <span class=\"token keyword\">if</span> <span class=\"token builtin\">len</span><span class=\"token punctuation\">(</span>answer<span class=\"token punctuation\">)</span> <span class=\"token operator\">==</span> n<span class=\"token operator\">-</span><span class=\"token number\">1</span><span class=\"token punctuation\">:</span> <span class=\"token keyword\">break</span><span class=\"token punctuation\">;</span>\n\n    <span class=\"token keyword\">return</span> <span class=\"token builtin\">sum</span><span class=\"token punctuation\">(</span>answer<span class=\"token punctuation\">)</span></code></pre></div>\n<h4 id=\"javascript\" style=\"position:relative;\"><a href=\"#javascript\" aria-label=\"javascript 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>JavaScript</h4>\n<div class=\"gatsby-highlight\" data-language=\"javascript\"><pre class=\"language-javascript\"><code class=\"language-javascript\"><span class=\"token comment\">// minimum spanning tree</span>\n<span class=\"token keyword\">function</span> <span class=\"token function\">solution</span><span class=\"token punctuation\">(</span><span class=\"token parameter\">n<span class=\"token punctuation\">,</span> costs</span><span class=\"token punctuation\">)</span> <span class=\"token punctuation\">{</span>\n  <span class=\"token keyword\">let</span> answer <span class=\"token operator\">=</span> <span class=\"token number\">0</span>\n\n  <span class=\"token keyword\">let</span> group <span class=\"token operator\">=</span> <span class=\"token punctuation\">[</span><span class=\"token punctuation\">]</span>\n  <span class=\"token keyword\">let</span> visited <span class=\"token operator\">=</span> <span class=\"token punctuation\">{</span><span class=\"token punctuation\">}</span>\n  <span class=\"token keyword\">let</span> cnt <span class=\"token operator\">=</span> <span class=\"token number\">0</span>\n\n  costs<span class=\"token punctuation\">.</span><span class=\"token function\">sort</span><span class=\"token punctuation\">(</span><span class=\"token punctuation\">(</span><span class=\"token parameter\">a<span class=\"token punctuation\">,</span>b</span><span class=\"token punctuation\">)</span> <span class=\"token operator\">=></span> a<span class=\"token punctuation\">[</span><span class=\"token number\">2</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">-</span> b<span class=\"token punctuation\">[</span><span class=\"token number\">2</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">)</span>\n\n  <span class=\"token keyword\">let</span> i <span class=\"token operator\">=</span> <span class=\"token number\">0</span>\n  <span class=\"token keyword\">while</span><span class=\"token punctuation\">(</span>costs<span class=\"token punctuation\">.</span>length <span class=\"token operator\">></span> i <span class=\"token operator\">&amp;&amp;</span> n <span class=\"token operator\">-</span> <span class=\"token number\">1</span> <span class=\"token operator\">></span> cnt <span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span>\n    <span class=\"token keyword\">let</span> isVisited0 <span class=\"token operator\">=</span> visited<span class=\"token punctuation\">[</span>costs<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span><span class=\"token number\">0</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">?</span> <span class=\"token boolean\">true</span> <span class=\"token operator\">:</span> <span class=\"token boolean\">false</span>\n    <span class=\"token keyword\">let</span> isVisited1 <span class=\"token operator\">=</span> visited<span class=\"token punctuation\">[</span>costs<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span><span class=\"token number\">1</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">?</span> <span class=\"token boolean\">true</span> <span class=\"token operator\">:</span> <span class=\"token boolean\">false</span>\n\n    <span class=\"token keyword\">if</span><span class=\"token punctuation\">(</span>isVisited0 <span class=\"token operator\">&amp;&amp;</span> isVisited1<span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span>\n      <span class=\"token comment\">// s, d visited -> group check</span>\n      <span class=\"token keyword\">let</span> groupNum <span class=\"token operator\">=</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 operator\">-</span><span class=\"token number\">1</span><span class=\"token punctuation\">]</span>\n      <span class=\"token keyword\">for</span><span class=\"token punctuation\">(</span><span class=\"token keyword\">let</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> group<span class=\"token punctuation\">.</span>length<span class=\"token punctuation\">;</span> j<span class=\"token operator\">++</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span>\n        <span class=\"token keyword\">if</span><span class=\"token punctuation\">(</span>groupNum<span class=\"token punctuation\">[</span><span class=\"token number\">0</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">==</span> <span class=\"token operator\">-</span><span class=\"token number\">1</span><span class=\"token punctuation\">)</span>\n          groupNum<span class=\"token punctuation\">[</span><span class=\"token number\">0</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> group<span class=\"token punctuation\">[</span>j<span class=\"token punctuation\">]</span><span class=\"token punctuation\">.</span><span class=\"token function\">indexOf</span><span class=\"token punctuation\">(</span>costs<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span><span class=\"token number\">0</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">)</span> <span class=\"token operator\">></span> <span class=\"token operator\">-</span><span class=\"token number\">1</span> <span class=\"token operator\">?</span> j <span class=\"token operator\">:</span> <span class=\"token operator\">-</span><span class=\"token number\">1</span>\n\n        <span class=\"token keyword\">if</span><span class=\"token punctuation\">(</span>groupNum<span class=\"token punctuation\">[</span><span class=\"token number\">1</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">==</span> <span class=\"token operator\">-</span><span class=\"token number\">1</span><span class=\"token punctuation\">)</span>\n          groupNum<span class=\"token punctuation\">[</span><span class=\"token number\">1</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> group<span class=\"token punctuation\">[</span>j<span class=\"token punctuation\">]</span><span class=\"token punctuation\">.</span><span class=\"token function\">indexOf</span><span class=\"token punctuation\">(</span>costs<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span><span class=\"token number\">1</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">)</span> <span class=\"token operator\">></span> <span class=\"token operator\">-</span><span class=\"token number\">1</span> <span class=\"token operator\">?</span> j <span class=\"token operator\">:</span> <span class=\"token operator\">-</span><span class=\"token number\">1</span>\n\n        <span class=\"token keyword\">if</span><span class=\"token punctuation\">(</span>groupNum<span class=\"token punctuation\">[</span><span class=\"token number\">0</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">!=</span> <span class=\"token operator\">-</span><span class=\"token number\">1</span> <span class=\"token operator\">&amp;&amp;</span> groupNum<span class=\"token punctuation\">[</span><span class=\"token number\">1</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">!=</span> <span class=\"token operator\">-</span><span class=\"token number\">1</span><span class=\"token punctuation\">)</span>\n          <span class=\"token keyword\">break</span><span class=\"token punctuation\">;</span>\n      <span class=\"token punctuation\">}</span>\n\n      <span class=\"token comment\">// 1. same group -> continue</span>\n      <span class=\"token keyword\">if</span><span class=\"token punctuation\">(</span>groupNum<span class=\"token punctuation\">[</span><span class=\"token number\">0</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">==</span> groupNum<span class=\"token punctuation\">[</span><span class=\"token number\">1</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">)</span> <span class=\"token punctuation\">{</span>\n        i<span class=\"token operator\">++</span>\n        <span class=\"token keyword\">continue</span>\n      <span class=\"token punctuation\">}</span>\n\n      <span class=\"token comment\">// 2. diff group -> union group, cnt ++, answer += cost</span>\n      group<span class=\"token punctuation\">[</span>groupNum<span class=\"token punctuation\">[</span><span class=\"token number\">0</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> group<span class=\"token punctuation\">[</span>groupNum<span class=\"token punctuation\">[</span><span class=\"token number\">0</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">.</span><span class=\"token function\">concat</span><span class=\"token punctuation\">(</span>group<span class=\"token punctuation\">[</span>groupNum<span class=\"token punctuation\">[</span><span class=\"token number\">1</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">)</span>\n      group<span class=\"token punctuation\">.</span><span class=\"token function\">splice</span><span class=\"token punctuation\">(</span>groupNum<span class=\"token punctuation\">[</span><span class=\"token number\">1</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">,</span> <span class=\"token number\">1</span><span class=\"token punctuation\">)</span>\n\n    <span class=\"token punctuation\">}</span>\n    <span class=\"token keyword\">else</span> <span class=\"token keyword\">if</span><span class=\"token punctuation\">(</span>isVisited0<span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span>\n      <span class=\"token comment\">// s visited</span>\n\n      <span class=\"token comment\">// add d to visited</span>\n      visited<span class=\"token punctuation\">[</span>costs<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span><span class=\"token number\">1</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> <span class=\"token boolean\">true</span>\n\n      <span class=\"token comment\">// add d to group</span>\n      group<span class=\"token punctuation\">.</span><span class=\"token function\">some</span><span class=\"token punctuation\">(</span><span class=\"token parameter\">g</span> <span class=\"token operator\">=></span> <span class=\"token punctuation\">{</span>\n        <span class=\"token keyword\">if</span><span class=\"token punctuation\">(</span>g<span class=\"token punctuation\">.</span><span class=\"token function\">indexOf</span><span class=\"token punctuation\">(</span>costs<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span><span class=\"token number\">0</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">)</span> <span class=\"token operator\">></span> <span class=\"token operator\">-</span><span class=\"token number\">1</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span>\n          g<span class=\"token punctuation\">.</span><span class=\"token function\">push</span><span class=\"token punctuation\">(</span>costs<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span><span class=\"token number\">1</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">)</span>\n          <span class=\"token keyword\">return</span> <span class=\"token boolean\">true</span>\n        <span class=\"token punctuation\">}</span>\n        <span class=\"token keyword\">return</span> <span class=\"token boolean\">false</span>\n      <span class=\"token punctuation\">}</span><span class=\"token punctuation\">)</span>\n    <span class=\"token punctuation\">}</span>\n    <span class=\"token keyword\">else</span> <span class=\"token keyword\">if</span><span class=\"token punctuation\">(</span>isVisited1<span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span>\n      <span class=\"token comment\">// d visited</span>\n\n      <span class=\"token comment\">// add s to visited</span>\n      visited<span class=\"token punctuation\">[</span>costs<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span><span class=\"token number\">0</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> <span class=\"token boolean\">true</span>\n\n      <span class=\"token comment\">// add s to group</span>\n      group<span class=\"token punctuation\">.</span><span class=\"token function\">some</span><span class=\"token punctuation\">(</span><span class=\"token parameter\">g</span> <span class=\"token operator\">=></span> <span class=\"token punctuation\">{</span>\n        <span class=\"token keyword\">if</span><span class=\"token punctuation\">(</span>g<span class=\"token punctuation\">.</span><span class=\"token function\">indexOf</span><span class=\"token punctuation\">(</span>costs<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span><span class=\"token number\">1</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">)</span> <span class=\"token operator\">></span> <span class=\"token operator\">-</span><span class=\"token number\">1</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">{</span>\n          g<span class=\"token punctuation\">.</span><span class=\"token function\">push</span><span class=\"token punctuation\">(</span>costs<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</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\">return</span> <span class=\"token boolean\">true</span>\n        <span class=\"token punctuation\">}</span>\n        <span class=\"token keyword\">return</span> <span class=\"token boolean\">false</span>\n      <span class=\"token punctuation\">}</span><span class=\"token punctuation\">)</span>\n    <span class=\"token punctuation\">}</span>\n    <span class=\"token keyword\">else</span> <span class=\"token punctuation\">{</span>\n      <span class=\"token comment\">// not visited s, d</span>\n\n      <span class=\"token comment\">// add s and d to visited</span>\n      visited<span class=\"token punctuation\">[</span>costs<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span><span class=\"token number\">0</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> <span class=\"token boolean\">true</span>\n      visited<span class=\"token punctuation\">[</span>costs<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span><span class=\"token number\">1</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">]</span> <span class=\"token operator\">=</span> <span class=\"token boolean\">true</span>\n\n      <span class=\"token comment\">// add new group</span>\n      group<span class=\"token punctuation\">.</span><span class=\"token function\">push</span><span class=\"token punctuation\">(</span><span class=\"token punctuation\">[</span>costs<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span><span class=\"token number\">0</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">,</span> costs<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span><span class=\"token number\">1</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">]</span><span class=\"token punctuation\">)</span>\n    <span class=\"token punctuation\">}</span>\n\n    answer <span class=\"token operator\">+=</span> costs<span class=\"token punctuation\">[</span>i<span class=\"token punctuation\">]</span><span class=\"token punctuation\">[</span><span class=\"token number\">2</span><span class=\"token punctuation\">]</span>\n    i<span class=\"token operator\">++</span>\n    cnt <span class=\"token operator\">++</span>\n  <span class=\"token punctuation\">}</span>\n\n  <span class=\"token keyword\">return</span> answer<span class=\"token punctuation\">;</span>\n<span class=\"token punctuation\">}</span></code></pre></div>\n<br>\n<br>","fields":{"slug":"/posts/algorithm-problem/programmers/programmers-42861","tagSlugs":["/tag/알고리즘-문제풀이/","/tag/프로그래머스/","/tag/greedy/"]},"frontmatter":{"date":"2021-10-28T11:48:32.169Z","description":"알고리즘 문제풀이 : 프로그래머스/섬 연결하기/42861","tags":["알고리즘 문제풀이","프로그래머스","greedy"],"title":"[알고문풀] 프로그래머스 : 섬 연결하기","socialImage":null}}},"pageContext":{"slug":"/posts/algorithm-problem/programmers/programmers-42861"}},"staticQueryHashes":["251939775","401334301","825871152"]}