2040. Game of Lines

单点时限: 2.0 sec

内存限制: 256 MB

Farmer John has challenged Bessie to the following game: FJ has a board with dots marked at N (2 <= N <= 200) distinct lattice points. Dot i has the integer coordinates X_i and Y_i (-1,000 <= X_i <= 1,000; -1,000 <= Y_i <= 1,000).

Bessie can score a point in the game by picking two of the dots and drawing a straight line between them; however, she is not allowed to draw a line if she has already drawn another line that is parallel to that line. Bessie would like to know her chances of winning, so

she has asked you to help find the maximum score she can obtain.

输入格式

  • Line 1: A single integer: N

  • Lines 2..N+1: Line i+1 describes lattice point i with two space-separated integers: X_i and Y_i.

输出格式

  • Line 1: A single integer representing the maximal number of lines Bessie can draw, no two of which are parallel.

样例

Input
4
-1 1
-2 0
0 0
1 1
Output
4
OUTPUT DETAILS:
Bessie can draw lines of the following four slopes: -1, 0, 1/3, and 1.

26 人解决,29 人已尝试。

38 份提交通过,共有 89 份提交。

3.9 EMB 奖励。

创建: 14 年,7 月前.

修改: 5 年,1 月前.

最后提交: 1 年,10 月前.

来源: USACO

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