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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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2013-08-28 09:17:26 P_Quantum
Finally accepted..!! Silly mistake costed me many WA.. |
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2013-07-10 05:01:21 Geanyous
lol printing "%d" instead of "%lld" cost me an WA.. |
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2013-06-25 16:49:53 Erti-Chris Eelmaa
0.49 :-)) |
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2013-06-19 19:48:22 Vipul Pandey
got AC in the first attempt! just use merge sort with a bit modification. But a good one to learn a new thing. |
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2013-06-12 09:38:08 virtuazx
Be careful about the typecasting and longlong stuff....It kills a lot of your time!! |
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2013-04-20 18:51:16 ওয়াসী (Wasi)
AC at first try... Last edit: 2013-08-21 15:01:40 |
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2013-04-15 16:21:46 Tony Stark
I have to agree with mister Kent. Last edit: 2013-04-03 13:03:25 |
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2013-04-15 16:21:46 luccasiau
Binary Indexed Trees are much more cooler than merge sort :) |
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2013-04-15 16:21:46 ankitsablok89
Easy one with Merge Sort :) |
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2013-04-15 16:21:46 suyog patil
easy 1 with merge sort!!! try ur college assignment program..:P |