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#3663. 最大的三角形

Estadísticas

三条无限延伸的直线可以构成一个三角形,除非它们交于同一点,或者其中某些直线相互平行。

给定一组无限延伸的直线,由其中任意三条直线所能构成的三角形的最大周长是多少?

输入格式

输入的第一行包含一个整数 $n$ ($3 \le n \le 100$),表示直线的数量。 接下来的 $n$ 行描述了这组直线。第 $i$ 行包含四个整数 $x_1, y_1, x_2, y_2$ ($-10\,000 \le x_1, y_1, x_2, y_2 \le 10\,000$),其中 $(x_1, y_1)$ 和 $(x_2, y_2)$ 是位于第 $i$ 条直线上的两个不同点。

输出格式

输出一个实数,表示由三条直线所能构成的三角形的最大周长。如果你的输出与正确答案的绝对误差或相对误差不超过 $10^{-5}$,则被视为正确。 如果给定的直线无法构成任何三角形,则输出 no triangle

样例

样例输入 1

3
0 0 0 1
0 0 1 0
0 1 1 0

样例输出 1

3.4142135624

样例输入 2

3
0 0 0 1
0 0 1 0
0 0 1 1

样例输出 2

no triangle

样例输入 3

4
0 0 0 1
0 4 3 0
0 0 1 0
-1 -1 1 1

样例输出 3

12.0000000000

Figure 1. 三条无限延伸的直线构成的三角形

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