A8121. Points
编程题
普及/提高-
知识点
题目描述
You are given $N$ points on a plane. Write a program which will find the sum of squares of distances between all pairs of points.
输入格式
The first line of input contains one integer number $N$ ( $1<=N<=100000$ ) — the number of points. Each of the following $N$ lines contain two integer numbers $X$ and $Y$ ( $-10000<=X,Y<=10000$ ) — the coordinates of points. Two or more points may coincide.
输出格式
The only line of output should contain the required sum of squares of distances between all pairs of points.
输入输出样例
输入 #1
4 1 1 -1 -1 1 -1 -1 1
输出 #1
32