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.


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 should be printed on a single line.


-45 22 42 -16
-41 -27 56 30
-36 53 -37 77
-36 30 -75 -46
26 -38 -10 62
-32 -54 -6 45


hide comments
ankit_programs: 2021-10-15 13:43:23

Hi,You must be here in comment sectopn after getting so many TLES.
The reason for TLE is not your logic instead its STL. Dont use any Stl library like Map,unorderd_map,vector,lower_bound. Implement your own functions.

I got 3≈4 TLES due to STL the implement My own functions and used simple array[] and AC.

4444: 2021-05-13 20:51:42

Got TLE for:
[1] unorder_map
[2] arrays with lower_bound, upper_bound

AC after using arrays and equal_range.

lamda_cdm_10: 2020-11-20 16:54:17

Use arrays and then binary search, STL implementation gives TLE

kya_bantai: 2020-10-08 06:16:31

after this try abcdef problem on spoj

dhruvgheewala: 2020-09-16 09:30:15

Getting TLE only, I have used MIM + (map, unordered map with good hash fxn, binary search, C++ lower_bound & upper_bound on vector after sorting it). Still getting TLE. Anyone suggest something or any other technique.

wille_25: 2020-08-01 05:41:36

if you do ABCDEF problem first ...its is a piece of cake for you ...same logic;

overthinker_72: 2020-06-07 12:58:36

upper bound and lower bound can help :)

shivamojha99: 2020-06-04 14:20:26

Can anyone tell me why map.find() isn't working although its complexity is log(n) too, and why using vectors get AC but not with Map function??

sandeep48: 2020-06-04 07:30:55

(n square)log(n) is working

brokeboy: 2020-05-04 13:35:26

STL maps gave TLE. Use array and sort instead.

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