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
jmr99: 2018-03-16 19:57:39

how to solve this using #graph-theory #number-theory #shortest-path pls somebody share the idea .

mranderson: 2018-03-16 19:52:03

use long long int for the count

jmr99: 2018-03-16 16:24:21

Last edit: 2018-03-16 19:52:08
jmr99: 2018-03-16 12:15:54

hint : : use BIT or Merge
seriously invested more than 4 hours to come up with sol.. nd debugged a lot of times to understand the flow of code nd finally ac in 1go !!! gys try something new rather than merge ..go for hacker-earth tut for this.

Last edit: 2018-03-16 19:55:46
kkislay20: 2018-03-16 12:01:15

I'm getting WA!!! Somebody please help.

https://ide.geeksforgeeks.org/UnP3Wza3wR

ash_maurya: 2018-03-16 07:15:19

@addy1397 There are n distinct numbers in the problem, none of them are repeated. Some of your random inputs are invalid.

zephyr_96: 2018-02-26 22:01:11

Use BigInteger (number of inversions) for java else you will get WA.

Last edit: 2018-02-26 22:02:24
saurabh987: 2018-01-14 14:14:47

my 100th :) using BIT

ultra_7: 2017-12-31 17:32:15

Make sure to use long long in c++

sagarthecoder: 2017-12-28 11:14:17

I used segment tree.
But gives TLE...


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