4sum II, is a LeetCode problem. In this post we will see how we can solve this challenge in C++

Problem Description

Given four lists A, B, C, D of integer values, compute how many tuples (i, j, k, l) there are such that A[i] + B[j] + C[k] + D[l] is zero.

To make problem a bit easier, all A, B, C, D have same length of N where 0 ≤ N ≤ 500. All integers are in the range of -228 to 228 - 1 and the result is guaranteed to be at most 231 - 1.


Input: A = [ 1, 2] B = [-2,-1] C = [-1, 2] D = [ 0, 2]


You can find the full details of the problem 4sum Ii at LeetCode

Solution: Please check the main.cpp snippet for the solution.

This solution originally posted at: Github by @kamyu104