DCEPC206 - Its a Murder!

Once detective Saikat was solving a murder case. While going to the crime scene he took the stairs and saw that a number is written on every stair. He found it suspicious and decides to remember all the numbers that he has seen till now. While remembering the numbers he found that he can find some pattern in those numbers. So he decides that for each number on the stairs he will note down the sum of all the numbers previously seen on the stairs which are smaller than the present number. Calculate the sum of all the numbers written on his notes diary.


First line gives T, number of test cases.

2T lines follow.

First line gives you the number of stairs N

Next line gives you N numbers written on the stairs.


For each test case output one line giving the final sum for each test case.




All numbers will be between 0 and 10^6.


1 5 3 6 4

Output: 15

hide comments
Gaurav sharma: 2014-12-28 05:39:28

I'm getting wrong ans... plz give me d special test case..

vivek: 2014-12-06 19:06:46

After one TLE accepted B|

Giribalaji: 2014-09-18 12:35:21

Can someone please explain the given test-case? I am stuck there itself ..

||N0VICE||: 2014-08-08 18:16:53

Nice prblm :)

Narendra yadav: 2014-07-24 22:17:00

Is it solvable in O(n) ?
Solved it using BIT. But my silly mistakes cost me many WA.

785227: 2014-07-01 08:47:35

Beware of overflows. To avoid that, use long long throughout your code :)

785227: 2014-07-01 08:38:22

Handle the overflows during multiplication. Lots of WAs because of that

monera: 2014-05-27 07:41:09

My 50th :D

Vipul Pandey: 2014-01-05 20:50:02

remember "sum of all the numbers previously seen on the stairs which are smaller than the present number" and not smaller or equal.Equal costed me a WA. But still it is a nice one!

Ouditchya Sinha: 2013-09-21 11:13:31

A lot of server instability. Using unsigned long long is faster than long long. Can anyone explain please? :)

Added by:dce coders
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Source limit:50000B
Memory limit:1536MB
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