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180. Inversions
time limit per test: 0.25 sec.
memory limit per test: 4096 KB
input: standard
output: standard
There are N integers (1<=N<=65537) A1, A2,.. AN (0<=Ai<=10^9). You need to find amount of such pairs (i, j) that 1<=i<j<=N and A[i]>A[j].
Input
The first line of the input contains the number N. The second line contains N numbers A1...AN.
Output
Write amount of such pairs.
Sample test(s)
Input
5
2 3 1 5 4
Output
3
Author:
Stanislav Angelyuk
Resource:
Saratov ST team Spring Contest #1
Date:
18.05.2003
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