SUMFOUR  4 values whose sum is 0
The SUM problem can be formulated as follows: given four lists A, B, C, D of integer values, compute how many quadruplet (a, b, c, d ) belongs to A x B x C x D are such that a + b + c + d = 0 . In the following, we assume that all lists have the same size n
Input
The first line of the input file contains the size of the lists n (this value can be as large as 4000). We then have n lines containing four integer values (with absolute value as large as 2^{28} ) that belong respectively to A, B, C and D .
(Edited: n <= 2500)
Output
Output should be printed on a single line.
Example
Input: 6 45 22 42 16 41 27 56 30 36 53 37 77 36 30 75 46 26 38 10 62 32 54 6 45 Output: 5
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anroc:
20170418 00:39:58
You can do it in 0.08s by using Feynman's algorithm. 

epsilonalpha:
20170418 00:02:30
TLE with lower bound and upper bound.


amandal799:
20170324 21:57:49
simple sorting and equal_range ...AC in one go 

scorpion_ajay:
20170318 17:22:59
its just simple.... just upper_bound and lower_bound thats it!


anroc:
20170310 06:22:55
Last edit: 20170424 23:33:14 

nilabja16180:
20170309 16:33:58
use equal_range, if you get TLE with lower and upper bound!


sonudoo:
20170205 12:24:33
If using unordered_map, choose C++14(g++ 5.1) as compiler. 

up79:
20170130 09:19:06
o(n^2) simple logic give you TLE :( but when u use "reserve" keyword for ur unordered map it is going to be accepted :( dont know why ! but finally AC ! 

souvik23:
20170125 21:04:49
Simple O((n^2)logn) using unordered_map without calling "reserve" function. 

vunnamtej:
20170125 17:57:44
thanks to @Shubham Gupta 
Added by:  Abhilash I 
Date:  20070206 
Time limit:  1.419s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ERL JSRHINO NODEJS PERL6 VB.NET 
Resource:  South western 0506 