4Sum II
Implement fourSumCount
You're given four integer arrays of the same length n. Count how many index quadruples (i, j, k, l) — one index chosen into each array — make the four selected values add up to exactly zero.
Example 1:
Input: nums1 = [4,-3], nums2 = [1,-2], nums3 = [-1,3], nums4 = [2,-4]
Output: 2
Example 2:
Input: nums1 = [0,0], nums2 = [0,0], nums3 = [0,0], nums4 = [0,0]
Output: 16
Example 3:
Input: nums1 = [1,1], nums2 = [1,1], nums3 = [1,1], nums4 = [1,1]
Output: 0
+ 6 hidden test cases run on Submit.
Constraints:
- ●
n == nums1.length == nums2.length == nums3.length == nums4.length - ●
1 ≤ n ≤ 8 - ●
-50 ≤ nums1[i], nums2[i], nums3[i], nums4[i] ≤ 50
nums1 =
[4, -3]
nums2 =
[1, -2]
nums3 =
[-1, 3]
nums4 =
[2, -4]