SPOJ.com - Problem DIG

DIG - DIAGONAL

no tags

You are a given a n sided convex polygon. Find total number of intersections of all diagonals.

Assume that all the intersection points are different.

If in case answer exceeds 10^9 + 7 , take modulo 10^9 + 7

1<=n<=10^8

First Line : T (number of test cases)

Next T line will contain N number of vertices

Number of intersections of diagonals as specified.

Input:
2
4
5

Output:
1
5

< Previous 1 2 Next >

	Alex Anderson: 2012-08-02 10:03:27 So in a hexagon, label the vertices 1,2,3,4,5,6. Then the intersection point between 1-4, 2-5, 3-6, counts as 3 separate intersections?
	Mitch Schwartz: 2012-08-02 10:03:27 There is some issue with the input file(s). My first submission ignored T and read until EOF, but got WA.
	Damian Straszak: 2012-08-02 10:03:27 This problem is not bad, but when writing a description try to avoid using abbreviations like "no".
	praveen123: 2012-08-02 10:03:27 This is my first problem added on SPOJ. For me it seems that it should go to tutorials section. I will later move it to tutorials section depending on no of accepted solutions .