Watch 10 video solutions for Number of Arithmetic Triplets, a easy level problem involving Array, Hash Table, Two Pointers. This walkthrough by Code with Alisha has 5,181 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
You are given a 0-indexed, strictly increasing integer array nums and a positive integer diff. A triplet (i, j, k) is an arithmetic triplet if the following conditions are met:
i < j < k,nums[j] - nums[i] == diff, andnums[k] - nums[j] == diff.Return the number of unique arithmetic triplets.
Example 1:
Input: nums = [0,1,4,6,7,10], diff = 3 Output: 2 Explanation: (1, 2, 4) is an arithmetic triplet because both 7 - 4 == 3 and 4 - 1 == 3. (2, 4, 5) is an arithmetic triplet because both 10 - 7 == 3 and 7 - 4 == 3.
Example 2:
Input: nums = [4,5,6,7,8,9], diff = 2 Output: 2 Explanation: (0, 2, 4) is an arithmetic triplet because both 8 - 6 == 2 and 6 - 4 == 2. (1, 3, 5) is an arithmetic triplet because both 9 - 7 == 2 and 7 - 5 == 2.
Constraints:
3 <= nums.length <= 2000 <= nums[i] <= 2001 <= diff <= 50nums is strictly increasing.