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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
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 |
hide comments
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2013-04-15 16:21:46 Dunno
sometimes it happens. |
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2013-04-15 16:21:46 coder
well well, my soln gets accepted in 0k.. lolz.. cant understand the logic how spoj calculates memory consumed. :P |
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2013-04-15 16:21:46 Chetan Gupta
@Boopathi: for first test case: 3 3 1 2 the first line contains the number of elements in the array. so 3 is the number of elements and 3,1,2 are elements. |
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2013-04-15 16:21:46 Boopathi Rajaa
how is it that there are only 2 inversions in first case ??? 0,2 ; 0,3 ; 1,2 ; 1,3 => 4 inv Edit : The 2 inversions are (3,1) and (3,2). Read the problem statement carefully. Last edit: 2011-05-26 04:42:45 |