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.
Input
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.
Output
For every test output one line giving the number of inversions of A.
Example
Input: 2 3 3 1 2 5 2 3 8 6 1 Output: 2 5
hide comments
Komal:
20150719 11:51:23
for the number of inversions do use a 64 bit integer(long in java) Last edit: 20150719 11:51:55 

ice_cold:
20150714 17:55:54
i got it correct for one test case but i dont know how to apply it for t test cases , pls give a hint .


MAYANK NARULA:
20150712 23:16:54
Aah well somethings never change! Just don't forget to use long long..


rini22:
20150711 16:29:13
use long long 

chin:
20150702 10:53:20
AC in 2nd attempt!!....A very good application of Mergesort!! 

mohit:
20150628 18:32:31
mergesort .. AC after 4 WA!!! give special attention to type... 

THECOLDONE:
20150624 14:14:31
after reading BIT done it by merge algo


Aditya Kumar:
20150624 09:18:21
Be careful with overflows


Sahil:
20150620 15:42:51
You only need the inversion count in long long (guess why? look at the worst case for this problem).


[Mayank Pratap]:
20150620 05:22:08
After months finally AC :) 
Added by:  Paranoid Android 
Date:  20100306 
Time limit:  3.599s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: PERL6 