4Sum II
Given four integer arrays nums1, nums2, nums3, and nums4, all of length n, return the number of tuples (i, j, k, l) such that:
0 <= i, j, k, l < nnums1[i] + nums2[j] + nums3[k] + nums4[l] == 0
Example 1
Input
nums1 = [1,2], nums2 = [-2,-1], nums3 = [-1,2], nums4 = [0,2]Output
2There are two valid tuples:
(0, 0, 0, 1) and (1, 1, 0, 0), each producing a sum of 0.Example 2
Input
nums1 = [0], nums2 = [0], nums3 = [0], nums4 = [0]Output
1The only tuple uses all four zeros, so its sum is
0.Constraints
- n == nums1.length
- n == nums2.length
- n == nums3.length
- n == nums4.length
- 1 <= n <= 200
- -2^28 <= nums1[i], nums2[i], nums3[i], nums4[i] <= 2^28