INVCNT - Inversion Count
Let A\[0...n - 1\] be an array of n distinct positive integers. If i < j and A\[i\] > A\[j\] then the pair (i, j) is called an inversion of A. Given n and an array A your task is to find the number of inversions of A.
The first line contains t, the number of testcases followed by a blank space. Each of the t tests start with a number n (n <= 200000). Then n + 1 lines follow. In the ith line a number A\[i - 1\] is given (A\[i - 1\] <= 10^7). The (n + 1)th line is a blank space.
For every test output one line giving the number of inversions of A.
2 3 3 1 2 5 2 3 8 6 1