Problem Statement

Given four arrays of integers nums1, nums2, nums3, and nums4 of the same length n, return the count of tuples (i, j, k, l) such that:

• 0 <= i, j, k, l < n
• nums1[i] + nums2[j] + nums3[k] + nums4[l] == 0

Examples

Example 1:

• Input: nums1 = [1], nums2 = [-1], nums3 = [0], nums4 = [0]
• Expected Output: 1
• Justification: The one quadruplet that sum up to 0 is:
  • (1, -1, 0, 0)

Example 2:

• Input: nums1 = [0, 1], nums2 = [1, -1], nums3 = [-1, 0], nums4 = [1, -1]
• Expected Output: 4
• Justification: The four quadruplets that sum up to 0 are:
  • (0, 1, 0, -1)
  • (0, -1, 0, 1)
  • (1, -1, -1, 1)
  • (1, 1, -1, -1)

Example 3:

• Input: nums1 = [-1, 3], nums2 = [2, -3], nums3 = [3, 4], nums4 = [-4, -3]
• Expected Output: 3
• Justification: The three quadruplets that sum up to 0 are:
  • (-1, 2, 3, -4)
  • (3, -3, 4, -4)
  • (3, -3, 3, -3)

Try it yourself

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