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
 ratedx: 2015-09-25 09:04:36 @Varun Gambhir both ordered and unordered are giving tle in my case! What is your time complexity? kobe24: 2015-09-05 00:30:06 Last edit: 2015-09-05 00:52:55 earner: 2015-08-27 18:12:06 can anyone tell why the 10th test case is giving wrong answer? shaky99: 2015-08-11 12:17:08 10th test case gives WA.. can any one tell why?? Last edit: 2015-08-11 12:18:07 Abhinandan Agarwal: 2015-08-04 21:52:43 Use dynamic allocation of array in case you are using binary search approach. Bhuvnesh Jain: 2015-07-22 21:44:57 brilliant question with even brilliant test cases. knew that qsort() is slower than sort() in worst case complexity but never had test cases which led me to change qsort to sort.... but here CAUTION: use only sort or your own implementation of merge/heap sort... do not use quick sort at all... Hussein Aassem: 2015-07-08 02:00:51 a testcase must be added with all the 4000 the same number to overflow char .... check my submission Last edit: 2015-07-08 02:02:50 Liquid_Science: 2015-07-01 15:48:11 Nearly Impossible in java :( kshitij tripathi: 2015-06-30 14:47:43 Nice Question..don't use Long Long int !! :D Varun Gambhir: 2015-06-23 21:11:15 Ordered map in c++ gives TLE and unordered gives AC(after some optimisations). Finally AC. :D Last edit: 2015-06-23 21:11:36

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