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2 초 128 MB 160 24 19 22.353%

문제

무선 센서 네트워크는 여러 개의 센서로 구성된 네트워크를 의미한다. 각 센서는 센서가 위치한 곳의 온도, 소리, 기압 등을 조사한다.

홍준이는 아마존 이산화탄소 측정 단체(Amazon Carbon-dioxide Measurement, 약칭 ACM)에서 프로젝트를 하나 맡았다. 그 프로젝트는, 아마존에 있는 무선 센서 네트워크로 부터 얻은 탄소의 양을 알아내어 최근 10년 동안 국제 화석 연료 사용양을 구한다. 그 사용량은 세계 산소 전달에 중요한 역할을 한다. 아마존의 숲은 매우 커서 홍준이의 역할이 중요하다.

센서들은 유클리드 거리 d 안에 있는 센서들과 통신할 수 있다. 홍준이는 2차원 평면에서 n개의 센서에 대한 좌표가 주어졌을 때, 집합안에 있는 센서들이 서로 직접적으로 통신 가능한 집합의 최대 크기와 그 집합을 구해야 한다.

입력

입력의 첫 줄에는 센서의 개수 n과 센서끼리 직접적으로 통신 가능한 거리 d가 주어진다 (1 ≤ n ≤ 100, 1 ≤ d ≤ 10 000). 센서들의 번호는 1번 부터 n번까지 순서대로 매겨져 있고, 다음 n개의 줄에 센서 번호 순서대로 좌표 x, y가 주어진다 (-10 000 ≤ x, y ≤ 10 000).

출력

첫 줄에 집합 내에 있는 센서들끼리 서로 직접적으로 통신할 수 있는 집합의 최대 크기를 출력하고, 둘째 줄에 그 집합에 있는 센서들의 번호를 출력한다. 만약, 가능한 답이 여러 가지인 경우 그 중 아무거나 하나 출력한다.

예제 입력 1

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예제 출력 1

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[{"problem_id":"10058","problem_lang":"0","title":"\uc13c\uc11c \ub124\ud2b8\uc6cc\ud06c","description":"<p>\ubb34\uc120 \uc13c\uc11c \ub124\ud2b8\uc6cc\ud06c\ub294 \uc5ec\ub7ec \uac1c\uc758 \uc13c\uc11c\ub85c \uad6c\uc131\ub41c \ub124\ud2b8\uc6cc\ud06c\ub97c \uc758\ubbf8\ud55c\ub2e4. \uac01 \uc13c\uc11c\ub294 \uc13c\uc11c\uac00 \uc704\uce58\ud55c \uacf3\uc758 \uc628\ub3c4, \uc18c\ub9ac, \uae30\uc555 \ub4f1\uc744 \uc870\uc0ac\ud55c\ub2e4. <img alt=\"\" src=\"\/upload\/images\/sensor.png\" style=\"background-color:initial; float:right; margin:0px 0px 10px 10px\" \/><\/p>\r\n\r\n<p>\ud64d\uc900\uc774\ub294 \uc544\ub9c8\uc874 \uc774\uc0b0\ud654\ud0c4\uc18c \uce21\uc815 \ub2e8\uccb4(Amazon Carbon-dioxide Measurement, \uc57d\uce6d ACM)\uc5d0\uc11c \ud504\ub85c\uc81d\ud2b8\ub97c \ud558\ub098 \ub9e1\uc558\ub2e4. \uadf8 \ud504\ub85c\uc81d\ud2b8\ub294, \uc544\ub9c8\uc874\uc5d0 \uc788\ub294&nbsp;\ubb34\uc120 \uc13c\uc11c \ub124\ud2b8\uc6cc\ud06c\ub85c \ubd80\ud130 \uc5bb\uc740 \ud0c4\uc18c\uc758 \uc591\uc744 \uc54c\uc544\ub0b4\uc5b4 \ucd5c\uadfc 10\ub144 \ub3d9\uc548 \uad6d\uc81c&nbsp;\ud654\uc11d \uc5f0\ub8cc \uc0ac\uc6a9\uc591\uc744 \uad6c\ud55c\ub2e4. \uadf8 \uc0ac\uc6a9\ub7c9\uc740 \uc138\uacc4 \uc0b0\uc18c \uc804\ub2ec\uc5d0 \uc911\uc694\ud55c \uc5ed\ud560\uc744 \ud55c\ub2e4. \uc544\ub9c8\uc874\uc758 \uc232\uc740 \ub9e4\uc6b0 \ucee4\uc11c \ud64d\uc900\uc774\uc758 \uc5ed\ud560\uc774 \uc911\uc694\ud558\ub2e4.<\/p>\r\n\r\n<p>\uc13c\uc11c\ub4e4\uc740 \uc720\ud074\ub9ac\ub4dc \uac70\ub9ac d \uc548\uc5d0 \uc788\ub294 \uc13c\uc11c\ub4e4\uacfc \ud1b5\uc2e0\ud560 \uc218 \uc788\ub2e4. \ud64d\uc900\uc774\ub294 2\ucc28\uc6d0 \ud3c9\uba74\uc5d0\uc11c n\uac1c\uc758 \uc13c\uc11c\uc5d0 \ub300\ud55c \uc88c\ud45c\uac00 \uc8fc\uc5b4\uc84c\uc744 \ub54c, \uc9d1\ud569\uc548\uc5d0 \uc788\ub294 \uc13c\uc11c\ub4e4\uc774 \uc11c\ub85c \uc9c1\uc811\uc801\uc73c\ub85c \ud1b5\uc2e0&nbsp;\uac00\ub2a5\ud55c \uc9d1\ud569\uc758 \ucd5c\ub300 \ud06c\uae30\uc640 \uadf8 \uc9d1\ud569\uc744 \uad6c\ud574\uc57c \ud55c\ub2e4.<\/p>\r\n","input":"<p>\uc785\ub825\uc758 \uccab \uc904\uc5d0\ub294 \uc13c\uc11c\uc758 \uac1c\uc218 n\uacfc \uc13c\uc11c\ub07c\ub9ac \uc9c1\uc811\uc801\uc73c\ub85c \ud1b5\uc2e0 \uac00\ub2a5\ud55c&nbsp;\uac70\ub9ac d\uac00 \uc8fc\uc5b4\uc9c4\ub2e4&nbsp;(1&nbsp;&le; n&nbsp;&le; 100, 1&nbsp;&le; d&nbsp;&le; 10 000). \uc13c\uc11c\ub4e4\uc758 \ubc88\ud638\ub294 1\ubc88 \ubd80\ud130 n\ubc88\uae4c\uc9c0 \uc21c\uc11c\ub300\ub85c \ub9e4\uaca8\uc838 \uc788\uace0, \ub2e4\uc74c n\uac1c\uc758 \uc904\uc5d0 \uc13c\uc11c \ubc88\ud638 \uc21c\uc11c\ub300\ub85c \uc88c\ud45c x, y\uac00 \uc8fc\uc5b4\uc9c4\ub2e4 (-10 000&nbsp;&le; x, y&nbsp;&le; 10 000).<\/p>\r\n","output":"<p>\uccab \uc904\uc5d0&nbsp;\uc9d1\ud569 \ub0b4\uc5d0 \uc788\ub294 \uc13c\uc11c\ub4e4\ub07c\ub9ac \uc11c\ub85c \uc9c1\uc811\uc801\uc73c\ub85c \ud1b5\uc2e0\ud560 \uc218 \uc788\ub294 \uc9d1\ud569\uc758 \ucd5c\ub300 \ud06c\uae30\ub97c \ucd9c\ub825\ud558\uace0, \ub458\uc9f8 \uc904\uc5d0 \uadf8 \uc9d1\ud569\uc5d0 \uc788\ub294 \uc13c\uc11c\ub4e4\uc758 \ubc88\ud638\ub97c \ucd9c\ub825\ud55c\ub2e4. \ub9cc\uc57d, \uac00\ub2a5\ud55c \ub2f5\uc774 \uc5ec\ub7ec \uac00\uc9c0\uc778 \uacbd\uc6b0 \uadf8 \uc911 \uc544\ubb34\uac70\ub098 \ud558\ub098 \ucd9c\ub825\ud55c\ub2e4.<\/p>\r\n","hint":"","original":"0","problem_lang_code":"\ud55c\uad6d\uc5b4"},{"problem_id":"10058","problem_lang":"1","title":"Sensor Network","description":"<p><img alt=\"\" src=\"\/upload\/images\/sensor.png\" style=\"float:right; height:181px; width:322px\" \/>A wireless sensor network consists of autonomous sensors scattered in an environment where they monitor conditions such as temperature, sound, and pressure.<\/p>\r\n\r\n<p>Samantha is a researcher working on the Amazon Carbon-dioxide Measurement (ACM) project. In this project, a wireless sensor network in the Amazon rainforest gathers environmental information. The Amazon rainforest stores an amount of carbon equivalent to a decade of global fossil fuel emissions, and it plays a crucial role in the world&rsquo;s oxygen-transfer processes. Because of the huge size of this forest, changes in the forest affect not only the local environment but also global climate by altering wind and ocean current patterns. The goal of the ACM project is to help scientists better understand earth&rsquo;s complex ecosystems and the impact of human activities.<\/p>\r\n\r\n<p>Samantha has an important hypothesis and to test her hypothesis, she needs to find a subset of sensors in which each pair of sensors can communicate directly with each other. A sensor can communicate directly with any other sensor having distance at most d from it. In order for her experiments to be as accurate as possible, Samantha wants to choose as many sensors as possible.<\/p>\r\n\r\n<p>As one does not simply walk into the Amazon, Samantha cannot add new sensors or move those that are currently in place. So given the current locations of the sensors, she needs your help to find the largest subset satisfying her criteria. For simplicity, represent the location of each sensor as a point in a two-dimensional plane with the distance between two points being the usual Euclidean distance.<\/p>\r\n","input":"<p>The input consists of a single test case. The first line contains two integers n and d (1 &le; n &le; 100 and 1 &le; d &le; 10 000), where n is the number of sensors available and d is the maximum distance between sensors that can communicate directly. Sensors are numbered 1 to n. Each of the next n lines contains two integers x and y (&minus;10 000 &le; x, y &le; 10 000) indicating the sensor coordinates, starting with the first sensor.<\/p>\r\n","output":"<p>Display a maximum subset of sensors in which each pair of sensors can communicate directly. The first line of output should be the size of the subset. The second line of output should be the (one-based) indices of the sensors in the subset. If there are multiple such subsets, any one of them will be accepted.<\/p>\r\n","hint":"","original":"1","problem_lang_code":"\uc601\uc5b4"}]

출처

ACM-ICPC > World Finals > 2014 World Finals I번