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
affan12347: 2021-01-15 16:03:56

monka s . naive array approach doesnt work , gives tle

Last edit: 2021-01-15 16:04:21
tejasreddyk: 2021-01-14 16:29:27

monkagiga count normal variable and std::count messed me up

sudo_s: 2021-01-01 15:07:07

Very Weak test Cases.
try a={84, 2, 37, 3, 67, 82, 19, 97, 91, 63, 27, 6, 13, 90, 63, 89, 100, 60, 47, 96, 54, 26, 64, 50, 71, 16, 6, 40, 84, 93, 67, 85, 16, 22, 60 };
my solution gave output 245 but it got accepted , correct answer=290

[NG]: Your case is invalid (*distinct* integers).

Last edit: 2021-01-01 22:42:20
anurag_mishra: 2020-11-28 14:06:41

Take array size 10^7+1 to remove SIGSEGV error

samartha_5611: 2020-08-20 12:56:34

make bit array of size 2e5+5, otherwise Segmentation falut will come

coolboy7: 2020-07-30 15:26:02

answer will be in range of long long

robosapien: 2020-07-21 18:11:41

use long long.

dardev: 2020-07-03 16:48:44

The concept is covered very well here -> https://www.youtube.com/watch?v=7_AJfusC6UQ

mukul202: 2020-05-19 17:39:01

Just solved this question using:
1)merge sort
2)fenwick tree
3)segment tree
Now trying with tries:)

picchi_67: 2020-05-06 05:46:10

Can be Solved Easily with merge sort.
Great problem for BIT Practice....Use " Long Long Int ".
Hint: use element value.


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