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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 Akash Goel
changing the no of inversions to long long didnt help, still stuck at TLE. :( |
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2013-04-15 16:21:46 Aman Verma
Guya just long long dis cost me much .. not only change the inversion_count to long long but change the array holding it also to long long and no need to take the test case as long long and do use scanf and printf coz it also cost me 1 TLE :( but Finally AC :) <Use English, not internet gibberish. Comment left because it includes some relevant information. At least that's what I assume, because IT'S HARD TO READ!!> Last edit: 2012-12-20 07:53:47 |
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2013-04-15 16:21:46 natsu
Thanks a lot guys.Its true .got AC after taking long long int for the no. of inversions |
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2013-04-15 16:21:46 Yashodhan S. Katte
@Rishabh use printf instead of cout and see. |
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2013-04-15 16:21:46 Haidar Abboud
No need for merge sort - you can just view the problem as a standard BIT exercise :P |
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2013-04-15 16:21:46 Rishabh Baid
would O(n log n) get accepted ? I tried using merge sort but got TLE. |
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2013-04-15 16:21:46 StupidGuy
Use long long int to count inversions. |
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2013-04-15 16:21:46 spock
wohooo..just changed the number of inversions to long long and got accepted.. :) Last edit: 2012-07-01 06:01:53 |
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2013-04-15 16:21:46 data
@Anup use return 0 |
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2013-04-15 16:21:46 krishna_0507
what is this runtime error(NZEC)???m using merge sort correctly then y is it showing me then !!!!!i hv implemaented mah code code in c and used int main and returned 0 also.....then also it is showing me that error.....can anyone help me ???? thanks in advance.... |