{"componentChunkName":"component---src-templates-blog-post-js","path":"/algorithm/codility/lesson8/ 23-equiLeader/","result":{"data":{"site":{"siteMetadata":{"title":"Zayden","author":"[Your Name]","siteUrl":"https://gatsby-starter-bee.netlify.com","comment":{"disqusShortName":"","utterances":"JaeYeopHan/gatsby-starter-bee"},"sponsor":{"buyMeACoffeeId":"jbee"}}},"markdownRemark":{"id":"dd8d110d-a94e-5855-b78c-97195b849116","excerpt":"문제 설명 N개의 정수로 구성된 비어 있지 않은 배열 A가 주어집니다. 이 배열의 리더는 A의 요소 중 절반 이상에서 발생하는 값입니다. 이퀘이 리더는 0 ≤ S < N - 1이고 두 시퀀스 A0, A1, …, AS와 AS + 1, AS + 2, …, AN - 1이 같은 값의 리더를 갖는 인덱스 S입니다. 예를 들어 다음과 같은 배열 A가 주어집니다: 두 개의 이퀴 리더를 찾을 수 있습니다: 0, 시퀀스이기 때문입니다: (4) 및 (3, 4, 4, 4, 4, 2)는 값이…","html":"<h2 id=\"문제-설명\" style=\"position:relative;\"><a href=\"#%EB%AC%B8%EC%A0%9C-%EC%84%A4%EB%AA%85\" aria-label=\"문제 설명 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 설명</h2>\n<p>N개의 정수로 구성된 비어 있지 않은 배열 A가 주어집니다.</p>\n<p>이 배열의 리더는 A의 요소 중 절반 이상에서 발생하는 값입니다.</p>\n<p>이퀘이 리더는 0 ≤ S &#x3C; N - 1이고 두 시퀀스 A[0], A[1], …, A[S]와 A[S + 1], A[S + 2], …, A[N - 1]이 같은 값의 리더를 갖는 인덱스 S입니다.</p>\n<p>예를 들어 다음과 같은 배열 A가 주어집니다:</p>\n<div class=\"gatsby-highlight\" data-language=\"text\"><pre class=\"language-text\"><code class=\"language-text\">A[0] = 4\nA[1] = 3\nA[2] = 4\nA[3] = 4\nA[4] = 4\nA[5] = 2</code></pre></div>\n<p>두 개의 이퀴 리더를 찾을 수 있습니다:</p>\n<ul>\n<li>0, 시퀀스이기 때문입니다: (4) 및 (3, 4, 4, 4, 4, 2)는 값이 4인 동일한 리더를 갖습니다.</li>\n<li>2, 왜냐하면 시퀀스: (4, 3, 4) 및 (4, 4, 2)는 값이 4인 동일한 리더를 갖기 때문입니다.</li>\n</ul>\n<p>목표는 등호 리더의 수를 세는 것입니다.</p>\n<p>함수를 작성합니다:</p>\n<div class=\"gatsby-highlight\" data-language=\"javascript\"><pre class=\"language-javascript\"><code class=\"language-javascript\"><span class=\"token keyword\">function</span> <span class=\"token function\">solution</span><span class=\"token punctuation\">(</span><span class=\"token parameter\"><span class=\"token constant\">A</span></span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">;</span></code></pre></div>\n<p>이 함수는 비어 있지 않은 정수 배열 A가 주어졌을 때, N개의 정수로 구성된 등차수열의 개수를 반환합니다.</p>\n<p>예를 들어, 주어진</p>\n<div class=\"gatsby-highlight\" data-language=\"text\"><pre class=\"language-text\"><code class=\"language-text\">A[0] = 4\nA[1] = 3\nA[2] = 4\nA[3] = 4\nA[4] = 4\nA[5] = 2</code></pre></div>\n<p>이면 위에서 설명한 대로 함수는 2를 반환해야 합니다.</p>\n<p>다음 가정에 대한 효율적인 알고리즘을 작성합니다:</p>\n<ul>\n<li>N은 [1..100,000] 범위 내의 정수입니다;</li>\n<li>배열 A의 각 요소는 [-1,000,000,000..1,000,000,000] 범위 내의 정수입니다.</li>\n</ul>\n<h2 id=\"문제-접근\" style=\"position:relative;\"><a href=\"#%EB%AC%B8%EC%A0%9C-%EC%A0%91%EA%B7%BC\" aria-label=\"문제 접근 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 접근</h2>\n<p><em>배열을 두부분으로 나누어 생각한다, 그리고 동적계획법을 이용한다.</em></p>\n<p>예를들어</p>\n<div class=\"gatsby-highlight\" data-language=\"text\"><pre class=\"language-text\"><code class=\"language-text\">left = []\nright = [4, 3 ... 2]</code></pre></div>\n<p><strong>처음에 두 변수에 하나에는 빈 배열 또 다른 하나에는 배열의 모든 요소</strong></p>\n<ol>\n<li>배열을 순회하면서</li>\n<li>left 에는 요소를 추가하여 리더 요소 확인</li>\n<li>right 에는 요소를 삭제하여 리더 요소 확인</li>\n<li>두개 리더 요소가 같을때를 찾는다.</li>\n</ol>\n<div class=\"gatsby-highlight\" data-language=\"javascript\"><pre class=\"language-javascript\"><code class=\"language-javascript\"><span class=\"token keyword\">function</span> <span class=\"token function\">solution</span><span class=\"token punctuation\">(</span><span class=\"token parameter\"><span class=\"token constant\">A</span></span><span class=\"token punctuation\">)</span> <span class=\"token punctuation\">{</span>\n   <span class=\"token keyword\">let</span> result <span class=\"token operator\">=</span> <span class=\"token number\">0</span><span class=\"token punctuation\">;</span>\n\n   <span class=\"token keyword\">const</span> right <span class=\"token operator\">=</span> <span class=\"token punctuation\">{</span><span class=\"token punctuation\">}</span><span class=\"token punctuation\">;</span>\n   <span class=\"token keyword\">const</span> left <span class=\"token operator\">=</span> <span class=\"token punctuation\">{</span><span class=\"token punctuation\">}</span><span class=\"token punctuation\">;</span>\n   <span class=\"token keyword\">let</span> leftLength <span class=\"token operator\">=</span> <span class=\"token number\">0</span><span class=\"token punctuation\">;</span>\n   <span class=\"token keyword\">let</span> rightLength <span class=\"token operator\">=</span> <span class=\"token constant\">A</span><span class=\"token punctuation\">.</span>length<span class=\"token punctuation\">;</span>\n   <span class=\"token keyword\">let</span> leftLeader <span class=\"token operator\">=</span> <span class=\"token number\">0</span><span class=\"token punctuation\">;</span>\n   <span class=\"token keyword\">let</span> leftLeaderCount <span class=\"token operator\">=</span> <span class=\"token number\">0</span><span class=\"token punctuation\">;</span>\n\n   <span class=\"token constant\">A</span><span class=\"token punctuation\">.</span><span class=\"token function\">forEach</span><span class=\"token punctuation\">(</span><span class=\"token punctuation\">(</span><span class=\"token parameter\">value</span><span class=\"token punctuation\">)</span> <span class=\"token operator\">=></span> <span class=\"token punctuation\">{</span>\n       <span class=\"token keyword\">if</span> <span class=\"token punctuation\">(</span>right<span class=\"token punctuation\">.</span><span class=\"token function\">hasOwnProperty</span><span class=\"token punctuation\">(</span>value<span class=\"token punctuation\">)</span><span class=\"token punctuation\">)</span> <span class=\"token punctuation\">{</span>\n           right<span class=\"token punctuation\">[</span>value<span class=\"token punctuation\">]</span><span class=\"token operator\">++</span><span class=\"token punctuation\">;</span>\n       <span class=\"token punctuation\">}</span> <span class=\"token keyword\">else</span> <span class=\"token punctuation\">{</span>\n           right<span class=\"token punctuation\">[</span>value<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 punctuation\">}</span>\n   <span class=\"token punctuation\">}</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">;</span>\n\n   <span class=\"token constant\">A</span><span class=\"token punctuation\">.</span><span class=\"token function\">forEach</span><span class=\"token punctuation\">(</span><span class=\"token punctuation\">(</span><span class=\"token parameter\">value</span><span class=\"token punctuation\">)</span> <span class=\"token operator\">=></span> <span class=\"token punctuation\">{</span>\n       <span class=\"token keyword\">if</span> <span class=\"token punctuation\">(</span>left<span class=\"token punctuation\">.</span><span class=\"token function\">hasOwnProperty</span><span class=\"token punctuation\">(</span>value<span class=\"token punctuation\">)</span><span class=\"token punctuation\">)</span> <span class=\"token punctuation\">{</span>\n           left<span class=\"token punctuation\">[</span>value<span class=\"token punctuation\">]</span><span class=\"token operator\">++</span><span class=\"token punctuation\">;</span>\n       <span class=\"token punctuation\">}</span> <span class=\"token keyword\">else</span> <span class=\"token punctuation\">{</span>\n           left<span class=\"token punctuation\">[</span>value<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 punctuation\">}</span>\n\n       right<span class=\"token punctuation\">[</span>value<span class=\"token punctuation\">]</span><span class=\"token operator\">--</span><span class=\"token punctuation\">;</span>\n\n       leftLength<span class=\"token operator\">++</span><span class=\"token punctuation\">;</span>\n       rightLength<span class=\"token operator\">--</span><span class=\"token punctuation\">;</span>\n\n       <span class=\"token keyword\">if</span> <span class=\"token punctuation\">(</span>left<span class=\"token punctuation\">[</span>value<span class=\"token punctuation\">]</span> <span class=\"token operator\">></span> leftLeaderCount<span class=\"token punctuation\">)</span> <span class=\"token punctuation\">{</span>\n           leftLeader <span class=\"token operator\">=</span> value<span class=\"token punctuation\">;</span>\n           leftLeaderCount <span class=\"token operator\">=</span> left<span class=\"token punctuation\">[</span>value<span class=\"token punctuation\">]</span><span class=\"token punctuation\">;</span>\n       <span class=\"token punctuation\">}</span>\n\n       <span class=\"token keyword\">if</span> <span class=\"token punctuation\">(</span>\n           right<span class=\"token punctuation\">[</span>leftLeader<span class=\"token punctuation\">]</span> <span class=\"token operator\">></span> <span class=\"token punctuation\">(</span>rightLength <span class=\"token operator\">/</span> <span class=\"token number\">2</span><span class=\"token punctuation\">)</span> \n           <span class=\"token operator\">&amp;&amp;</span> leftLeaderCount <span class=\"token operator\">></span> <span class=\"token punctuation\">(</span>leftLength <span class=\"token operator\">/</span> <span class=\"token number\">2</span><span class=\"token punctuation\">)</span>\n       <span class=\"token punctuation\">)</span> <span class=\"token punctuation\">{</span>\n           result<span class=\"token operator\">++</span><span class=\"token punctuation\">;</span>\n       <span class=\"token punctuation\">}</span>\n   <span class=\"token punctuation\">}</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">;</span>\n\n   <span class=\"token keyword\">return</span> result<span class=\"token punctuation\">;</span>\n<span class=\"token punctuation\">}</span></code></pre></div>","frontmatter":{"title":"Codility Lesson 8 - EquiLeader","date":"July 17, 2023"}}},"pageContext":{"slug":"/algorithm/codility/lesson8/ 23-equiLeader/","previous":{"fields":{"slug":"/algorithm/codility/lesson8/ 22-dominator/"},"frontmatter":{"title":"Codility Lesson 8 - Dominator"}},"next":{"fields":{"slug":"/algorithm/codility/lesson9/ 24-maxProfit/"},"frontmatter":{"title":"Codility Lesson 9 - MaxProfit"}}}}}