INVCNT - Inversion Count

**题意： t组数据，每组数据开头n为数列元素个数，求逆序对个数。**

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

2
5