Type: Default 1000ms 256MiB

牛的距离

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Description

在一条数轴上有N(N$\leq$10000)头牛在不同的位置上,每头牛都计算到其它各头牛的距离。求这n*(n-1)个距离的总和。

Input Format

第一行:N 后面N行,每行一个整数,表示一头牛所在位置。

Output Format

一个整数。

Sample

input

5
1
5
3
2
4    


output

40



说明:
(1+2+3+4)+(4+3+2+1)
+(2+1+1+2)+(1+1+2+3)
+(3+2+1+1) = 40

Hint

时间限制:1s1 \text {s}

空间限制:256MB256 \text {MB}

20200810数组基本练习

Not Attended
Status
Done
Rule
ACM/ICPC
Problem
12
Start at
2020-8-10 9:48
End at
2020-8-11 9:48
Duration
24 hour(s)
Host
Partic.
43