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
Anubhav Gupta: 2015-10-31 14:06:41

BIT rocks!!!

free mind ;): 2015-09-19 15:03:58

use long long for calculating sum!
Nice one, after 1 year able to solve this. ;)

SangKuan: 2015-08-10 13:19:08

ac by mergesort . to many tle with common lisp,optimize after optimize,finally got ac.haha,no need to rewrite by c

rk: 2015-06-28 16:22:26

plz dont forget the zero case and declare array long long &finally done :)

r0bo_dart: 2015-06-25 09:31:40

Hint: one version of merge sort will fail coz we want to include m < n not m <= n....

Aditya Kumar: 2015-06-24 10:12:30

Better solve inversion count first!!

Baymax: 2015-05-27 22:59:11

did it with mergesort

i_am_looser: 2015-05-24 09:45:41

Good question =)

Madhav: 2015-04-02 11:40:28

good question!!

abhijeet gusain: 2015-02-19 21:10:30

@Gaurav necessary test cases are already given ... it may be that ur code has some input issues ...

Added by:dce coders
Time limit:1.259s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ASM64
Resource:Own Problem