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문제

데이터 과학자 앨리스는 데이터를 분석하는 일을 받았다. 각 데이터는 2차원 좌표 $(x, y)$로 구성된다.

데이터 분석은 $x$축에 평행한 $K$개의 선분을 2차원 상에서 찾는 과정이다. 구체적으로 아래의 값들을 결정해야한다.

  • 각 선분의 끝을 나타내는 $x$좌표 $0=p_0 < p_1 < \cdots < p_K = 50\ 000$, $i$번째 선분의 양 끝은 $p_{i-1}$과 $p_i$이다. $1 \leq i \leq K$
  • 각 선분의 $y$좌표 $m_1, m_2, \cdots, m_K$

물론 $m_1, m_2, \cdots, m_k$의 값들을 아무렇게나 결정하면 안 된다. 분석의 정확도를 높이기 위해서, 분석의 오차를 정의한 다음 오차가 최소가 되도록 값을 결정해 줄 것이다. 오차는 다음과 같이 정의한다.

  • 데이터 $(x, y)$의 오차는, $p_{i-1} \leq x < p_i$를 만족하는 $i$에 대해서 $|y - m_i|$으로 정의한다.
  • 전체 데이터에 대한 오차는 각 데이터 $(x, y)$의 오차의 합이다.

앨리스는 데이터 분석의 오차가 최소가 되도록 $p_0, \cdots, p_k$와 $m_1, \cdots, m_k$를 결정하고자 한다. 각 값을 적절히 결정했을 때, 데이터 분석의 오차의 최솟값을 구하시오.

입력

첫 번째 줄에 데이터의 개수 $N$과 찾아야하는 선분의 개수 $K$가 공백으로 구분되어 주어진다.

이후 $N$개의 줄에 각 데이터 $(x, y)$가 공백으로 구분되어 주어진다. 단, 모든 데이터의 $x$ 값은 다르다.

출력

데이터 분석의 오차가 최소가 되도록 $p_0,\cdots, p_k$와 $m_1,\cdots, m_k$의 값을 적절히 결정했을 때, 데이터 분석의 오차를 출력한다. 절대/상대 오차는 $10^{-4}$까지 허용한다.

제한

  • 주어지는 모든 수는 정수이다.
  • $1\leq N \leq 3\,000$
  • $1\leq K \leq \min(N, 10)$
  • $0\leq x < 50\,000$
  • $0\leq y \leq 1\,000$

서브태스크

번호배점제한
130

$N \leq 300$

270

추가 제약 조건이 없음.

예제 입력 1

6 2
1 1
2 2
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6 6

예제 출력 1

4.0000
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Each data point is represented as&nbsp;2-dimensional coordinates $(x, y)$.<\/p>\r\n\r\n<p>The task is to identify $K$ lines that are parallel to the $x$-axis on a 2-dimension plane, meeting the following criteria:<\/p>\r\n\r\n<ul>\r\n\t<li>The $i$-th line&#39;s endpoints&#39;&nbsp;coordinates are&nbsp;$p_{i-1}$ and&nbsp;$p_i$ where $1 \\leq i \\leq K$.<\/li>\r\n\t<li>Such&nbsp;coordinates must satisfy&nbsp;$0 = p_0 \\lt&nbsp;p_1 \\lt&nbsp;\\cdots \\lt&nbsp;p_k = 50\\ 000$.<\/li>\r\n\t<li>In addition, let $m_i$ be the representative value for the $i$-th line, to be chosen (see below).<\/li>\r\n<\/ul>\r\n\r\n<p>Alice shall not choose the values of $m_1, m_2, \\cdots, m_k$ arbitrarily. To increase accuracy of analysis, the error of analysis shall be defined first,&nbsp;and the values that minimize the error should be chosen. 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All $x$ coordinates will be unique.<\/p>\r\n","output":"<p>Output the smallest possible error of analysis when&nbsp;$p_0,\\cdots, p_k$ and&nbsp;$m_1,\\cdots, m_k$ are chosen appropriately by Alice.&nbsp;Your answer will be considered as correct if it has an absolute or relative error less than $10^{-4}$.<\/p>\r\n","hint":"","original":"0","html_title":"0","problem_lang_tcode":"English","limit":"<ul>\r\n\t<li>All numbers given in input will be integers.<\/li>\r\n\t<li>$1\\leq N \\leq 3\\,000$<\/li>\r\n\t<li>$1\\leq K \\leq \\min(N, 10)$<\/li>\r\n\t<li>$0\\leq x &lt; 50\\,000$<\/li>\r\n\t<li>$0\\leq y \\leq 1\\,000$<\/li>\r\n<\/ul>\r\n","subtask1":"<p>$N \\leq 300$<\/p>\r\n","subtask2":"<p>No additional restrictions on input.<\/p>\r\n"}]

출처

채점 및 기타 정보

  • 예제는 채점하지 않는다.