Count Special Quadruplets
Given a 0-indexed integer array nums, return the number of distinct quadruplets (a, b, c, d) such that:
nums[a] + nums[b] + nums[c] == nums[d], anda < b < c < d
Example 1
Input
nums = [1,2,3,6]Output
1The only quadruplet that satisfies the requirement is (0, 1, 2, 3) because 1 + 2 + 3 == 6.
Example 2
Input
nums = [3,3,6,4,5]Output
0There are no such quadruplets in [3, 3, 6, 4, 5].
Constraints
- 4 <= nums.length <= 50
- 1 <= nums[i] <= 100