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 228 ) 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

hide comments
Chandan Mittal: 2015-01-08 23:56:49

O(n^2 * log(n)) gives TLE. But why??? :(

ankit kumar sinha: 2015-01-01 14:14:07

dont use long long int. gives TLE

ashish kumar: 2014-12-29 13:55:20

wrong ans on test case 9

Miguel Oliveira: 2014-06-11 13:51:00

very weak test cases, it doesn't even have n up to 4000

Ehor Nechiporenko: 2010-02-23 11:24:23

Manish - the right answer 4^4 = 256

Last edit: 2010-10-21 05:27:15
Manish kumar: 2010-02-11 16:11:33

4
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
whats the answer for this input ? problem looks for distinct quadruplet, right ?

Ruslan Sennov: 2009-06-30 02:40:46

hint:
sort() in C++ runs faster than qsort in C


Added by:Abhilash I
Date:2007-02-06
Time limit:1.419s
Source limit:50000B
Memory limit:1536MB
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Resource:South western 05-06