시간 제한 메모리 제한 제출 정답 맞은 사람 정답 비율
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문제

당신은 웹 서핑을 하고 있었다. 당연히 광고 차단 기능도 없이, 그것도 인터넷 익스플로러로 말이다. 그러던 중 당신은 여러 개의 웹페이지에 올라온 광고 패널들에 재미있는 대회들이 광고된 것을 보게 되었다.

이 대회들은 대부분 간단한 질문에 답하는 형식이다. 예를 들자면 사진에 몇 개의 삼각형이나 정사각형, 직사각형이 있는지, 아니면 3개의 보기 중에서 정답을 고르는 문제 같은 것이다. 이렇게 간단한데도 불구하고 거기에는 좋은 상품들이 많이 걸려 있었다. 그러니 해볼 만 했다.

당첨될 기회를 높이기 위해서, 당신은 문제를 풀어 주는 간단한 프로그램을 만들기로 했다. 당신은 첫 번째 질문인, 사진 속에 몇 개의 정사각형이 있는지에 집중하기로 했고, 문제를 더욱 단순화하기 위해서 입력된 사진들은 선분이 아닌 직선만 포함하고 있으리라고 가정했다.

정의에 대해 좀 더 세밀하게 이야기하자면, 우리는 사진 속의 네 개의 직선 ℓ1, ℓ2, ℓ3, ℓ4들 중에서 ℓ1, ℓ3이 서로 평행하고, 이들이 ℓ2, ℓ4와는 수직이며, ℓ1과 ℓ3 사이의 거리가 ℓ2와 ℓ4 사이의 거리와 같을 때 이것이 정사각형을 이룬다고 말한다.

입력

첫 번째 줄에 사진 속의 직선의 개수를 의미하는 정수 n이 주어진다.  (1 ≤ n ≤ 2,000)

뒤의 n개의 줄에는 직선 각각에 대한 설명이 이어지는데, 직선들은 직선 위의 두 점의 좌표를 통해 주어지며, 구체적으로는 최대 10,000인 네 정수 x1, y1, x2, y2으로 주어진다. 이 직선은 (x1, y1)과 (x2, y2)를 지난다는 것이다.

두 점의 좌표는 다르다고 가정해도 좋다. 그리고 모든 직선은 다르다고 가정해도 좋다.

출력

그림 속의 직선들로 이루어진 정사각형의 개수를 한 개의 정수로 한 줄에 출력하라.

예제 입력 1

10
0 0 1 0
0 1 1 1
0 2 2 2
0 0 0 4
1 -1 1 0
2 -2 2 2
1 1 2 2
1 1 0 2
3 1 2 2
1 3 0 2

예제 출력 1

6

힌트

[{"problem_id":"10267","problem_lang":"0","title":"\uc0ac\uac01\ud615\uc740 \uba87 \uac1c?","description":"<p>\ub2f9\uc2e0\uc740 \uc6f9 \uc11c\ud551\uc744 \ud558\uace0 \uc788\uc5c8\ub2e4. \ub2f9\uc5f0\ud788 \uad11\uace0 \ucc28\ub2e8 \uae30\ub2a5\ub3c4 \uc5c6\uc774, \uadf8\uac83\ub3c4 \uc778\ud130\ub137 \uc775\uc2a4\ud50c\ub85c\ub7ec\ub85c \ub9d0\uc774\ub2e4. \uadf8\ub7ec\ub358 \uc911 \ub2f9\uc2e0\uc740 \uc5ec\ub7ec \uac1c\uc758 \uc6f9\ud398\uc774\uc9c0\uc5d0 \uc62c\ub77c\uc628 \uad11\uace0 \ud328\ub110\ub4e4\uc5d0 \uc7ac\ubbf8\uc788\ub294 \ub300\ud68c\ub4e4\uc774 \uad11\uace0\ub41c \uac83\uc744 \ubcf4\uac8c \ub418\uc5c8\ub2e4.<\/p>\r\n\r\n<p>\uc774 \ub300\ud68c\ub4e4\uc740 \ub300\ubd80\ubd84 \uac04\ub2e8\ud55c \uc9c8\ubb38\uc5d0 \ub2f5\ud558\ub294 \ud615\uc2dd\uc774\ub2e4. \uc608\ub97c \ub4e4\uc790\uba74 \uc0ac\uc9c4\uc5d0 \uba87 \uac1c\uc758 \uc0bc\uac01\ud615\uc774\ub098 \uc815\uc0ac\uac01\ud615, \uc9c1\uc0ac\uac01\ud615\uc774 \uc788\ub294\uc9c0, \uc544\ub2c8\uba74 3\uac1c\uc758 \ubcf4\uae30 \uc911\uc5d0\uc11c \uc815\ub2f5\uc744 \uace0\ub974\ub294 \ubb38\uc81c \uac19\uc740 \uac83\uc774\ub2e4. \uc774\ub807\uac8c \uac04\ub2e8\ud55c\ub370\ub3c4 \ubd88\uad6c\ud558\uace0 \uac70\uae30\uc5d0\ub294 \uc88b\uc740 \uc0c1\ud488\ub4e4\uc774 \ub9ce\uc774 \uac78\ub824 \uc788\uc5c8\ub2e4. \uadf8\ub7ec\ub2c8 \ud574\ubcfc \ub9cc \ud588\ub2e4.<\/p>\r\n\r\n<p>\ub2f9\ucca8\ub420 \uae30\ud68c\ub97c \ub192\uc774\uae30 \uc704\ud574\uc11c, \ub2f9\uc2e0\uc740 \ubb38\uc81c\ub97c \ud480\uc5b4 \uc8fc\ub294 \uac04\ub2e8\ud55c \ud504\ub85c\uadf8\ub7a8\uc744 \ub9cc\ub4e4\uae30\ub85c \ud588\ub2e4. \ub2f9\uc2e0\uc740 \uccab \ubc88\uc9f8 \uc9c8\ubb38\uc778, \uc0ac\uc9c4 \uc18d\uc5d0 \uba87 \uac1c\uc758 \uc815\uc0ac\uac01\ud615\uc774 \uc788\ub294\uc9c0\uc5d0 \uc9d1\uc911\ud558\uae30\ub85c \ud588\uace0, \ubb38\uc81c\ub97c \ub354\uc6b1 \ub2e8\uc21c\ud654\ud558\uae30 \uc704\ud574\uc11c \uc785\ub825\ub41c \uc0ac\uc9c4\ub4e4\uc740 \uc120\ubd84\uc774 \uc544\ub2cc \uc9c1\uc120\ub9cc \ud3ec\ud568\ud558\uace0 \uc788\uc73c\ub9ac\ub77c\uace0 \uac00\uc815\ud588\ub2e4.<\/p>\r\n\r\n<p>\uc815\uc758\uc5d0 \ub300\ud574 \uc880 \ub354 \uc138\ubc00\ud558\uac8c \uc774\uc57c\uae30\ud558\uc790\uba74, \uc6b0\ub9ac\ub294 \uc0ac\uc9c4 \uc18d\uc758 \ub124 \uac1c\uc758 \uc9c1\uc120 \u2113<sub>1<\/sub>, \u2113<sub>2<\/sub>, \u2113<sub>3<\/sub>, \u2113<sub>4<\/sub>\ub4e4 \uc911\uc5d0\uc11c&nbsp;\u2113<sub>1<\/sub>,&nbsp;\u2113<sub>3<\/sub>\uc774 \uc11c\ub85c \ud3c9\ud589\ud558\uace0, \uc774\ub4e4\uc774&nbsp;\u2113<sub>2<\/sub>,&nbsp;\u2113<sub>4<\/sub>\uc640\ub294 \uc218\uc9c1\uc774\uba70,&nbsp;\u2113<sub>1<\/sub>\uacfc&nbsp;\u2113<sub>3<\/sub> \uc0ac\uc774\uc758 \uac70\ub9ac\uac00&nbsp;\u2113<sub>2<\/sub>\uc640&nbsp;\u2113<sub>4<\/sub> \uc0ac\uc774\uc758 \uac70\ub9ac\uc640 \uac19\uc744 \ub54c \uc774\uac83\uc774 \uc815\uc0ac\uac01\ud615\uc744 \uc774\ub8ec\ub2e4\uace0 \ub9d0\ud55c\ub2e4.<\/p>\r\n","input":"<p>\uccab \ubc88\uc9f8 \uc904\uc5d0 \uc0ac\uc9c4 \uc18d\uc758 \uc9c1\uc120\uc758 \uac1c\uc218\ub97c \uc758\ubbf8\ud558\ub294 \uc815\uc218 n\uc774 \uc8fc\uc5b4\uc9c4\ub2e4.&nbsp;&nbsp;(1 &le; n &le; 2,000)<\/p>\r\n\r\n<p>\ub4a4\uc758 n\uac1c\uc758 \uc904\uc5d0\ub294 \uc9c1\uc120 \uac01\uac01\uc5d0 \ub300\ud55c \uc124\uba85\uc774 \uc774\uc5b4\uc9c0\ub294\ub370, \uc9c1\uc120\ub4e4\uc740 \uc9c1\uc120 \uc704\uc758 \ub450 \uc810\uc758 \uc88c\ud45c\ub97c \ud1b5\ud574 \uc8fc\uc5b4\uc9c0\uba70, \uad6c\uccb4\uc801\uc73c\ub85c\ub294 \ucd5c\ub300 10,000\uc778 \ub124 \uc815\uc218 x<sub>1<\/sub>, y<sub>1<\/sub>, x<sub>2<\/sub>, y<sub>2<\/sub>\uc73c\ub85c \uc8fc\uc5b4\uc9c4\ub2e4. \uc774 \uc9c1\uc120\uc740 (x<sub>1<\/sub>, y<sub>1<\/sub>)\uacfc (x<sub>2<\/sub>, y<sub>2<\/sub>)\ub97c \uc9c0\ub09c\ub2e4\ub294 \uac83\uc774\ub2e4.<\/p>\r\n\r\n<p>\ub450 \uc810\uc758 \uc88c\ud45c\ub294 \ub2e4\ub974\ub2e4\uace0 \uac00\uc815\ud574\ub3c4 \uc88b\ub2e4. \uadf8\ub9ac\uace0 \ubaa8\ub4e0 \uc9c1\uc120\uc740 \ub2e4\ub974\ub2e4\uace0 \uac00\uc815\ud574\ub3c4 \uc88b\ub2e4.<\/p>\r\n","output":"<p>\uadf8\ub9bc \uc18d\uc758 \uc9c1\uc120\ub4e4\ub85c \uc774\ub8e8\uc5b4\uc9c4 \uc815\uc0ac\uac01\ud615\uc758 \uac1c\uc218\ub97c \ud55c \uac1c\uc758 \uc815\uc218\ub85c \ud55c \uc904\uc5d0 \ucd9c\ub825\ud558\ub77c.<\/p>\r\n","hint":"","original":"0","problem_lang_code":"\ud55c\uad6d\uc5b4"},{"problem_id":"10267","problem_lang":"1","title":"How many squares?","description":"<p>While browsing the internet, of course using Internet Explorer without any adblocker, you have noticed a number of interesting competitions advertised in the panels on various webpages. In most of these competitions you need to answer a simple question, like how many triangles\/squares\/rectangles there are in a picture, or even choose the right answer out of three possibilities. Despite the simplicity of the task, it seems that there are many valuable prizes to be won. So there is definitely something to compete for!<\/p>\r\n\r\n<p>In order to increase your chances, you decided to write a simple program that will solve the problem for you. You decided to focus first on the question &ldquo;How many squares are there in the picture?&rdquo;, and to simplify the problem even more, you assume that the input picture consists only of a number of lines that are infinite in both directions. To be precise, we say that four lines \u2113<sub>1<\/sub>, \u2113<sub>2<\/sub>, \u2113<sub>3<\/sub>, \u2113<sub>4<\/sub> in the picture form a square if lines \u2113<sub>1<\/sub> and \u2113<sub>3<\/sub> are parallel to each other and perpendicular to \u2113<sub>2<\/sub> and \u2113<sub>4<\/sub>, and moreover the distance between \u2113<sub>1<\/sub> and \u2113<sub>3<\/sub> is the same as the distance between \u2113<sub>2<\/sub> and \u2113<sub>4<\/sub>.<\/p>\r\n","input":"<p>The first line of the input contains a single integer n (1 &le; n &le; 2 000), denoting the number of lines in the input picture. Then follow n lines, each containing a description of one line in the input picture. The line is given as a pair of distinct points lying on it. That is, the description consists of four integers x<sub>1<\/sub>, y<sub>1<\/sub>, x<sub>2<\/sub>, y<sub>2<\/sub>, each of them of absolute value at most 10 000, such that the line passes through points (x<sub>1<\/sub>, y<sub>1<\/sub>) and (x<sub>2<\/sub>, y<sub>2<\/sub>). You may assume that points (x<sub>1<\/sub>, y<sub>1<\/sub>) and (x<sub>2<\/sub>, y<sub>2<\/sub>) are different, and also that all the lines in the picture are pairwise different.<\/p>\r\n","output":"<p>Output exactly one line with one integer, denoting the total number of squares formed by the lines in the picture.<\/p>\r\n","hint":"","original":"1","problem_lang_code":"\uc601\uc5b4"}]