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
hide comments
Akash Goel:
2013-04-15 16:21:46
changing the no of inversions to long long didnt help, still stuck at TLE. :( |
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Aman Verma:
2013-04-15 16:21:46
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
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natsu:
2013-04-15 16:21:46
Thanks a lot guys.Its true .got AC after taking long long int for the no. of inversions |
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Yashodhan S. Katte:
2013-04-15 16:21:46
@Rishabh use printf instead of cout and see. |
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Haidar Abboud:
2013-04-15 16:21:46
No need for merge sort - you can just view the problem as a standard BIT exercise :P |
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Rishabh Baid:
2013-04-15 16:21:46
would O(n log n) get accepted ? I tried using merge sort but got TLE. |
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StupidGuy:
2013-04-15 16:21:46
Use long long int to count inversions. |
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spock:
2013-04-15 16:21:46
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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data:
2013-04-15 16:21:46
@Anup use return 0 |
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krishna_0507:
2013-04-15 16:21:46
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....
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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 |