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] ≤ 107). 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
amandal799:
2017-03-23 18:42:59
solved using binary search tree..AC in one go |
|
rohit9934:
2017-03-15 16:36:06
For Those who are looking for hints.
|
|
jeelapamy:
2017-03-09 10:39:55
ha ha long long |
|
anaar_13:
2017-03-03 16:20:51
too weak tests!!!!
|
|
shreeshiv:
2017-02-20 10:13:59
What is WA and AC??
|
|
nilabja16180:
2017-02-13 13:47:11
A great BIT problem |
|
fane_faiz:
2017-02-09 10:21:48
Don't forget to use long long, caused me 2 WA.
|
|
sks4903440:
2017-02-07 20:24:44
Don't forget to use long long. |
|
akash_23:
2017-02-07 18:53:16
did using BIT, easy AC! tag helped me to get the idea :P |
|
zhanbolat:
2017-01-22 17:32:14
I didn't get relation between graph theory and this problem.
|
Added by: | Paranoid Android |
Date: | 2010-03-06 |
Time limit: | 3.599s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: PERL6 |