# Number of Arithmetic Triplets

Easy
22
1
36.1% Acceptance

In this lab, you will implement a function `arithmeticTriplets(nums: number[], diff: number): number` that returns the number of unique arithmetic triplets. Your input will be 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`
• `nums[k] - nums[j] == diff`

Example:

``````arithmeticTriplets([0,1,4,6,7,10], 3)
// Output: 2
// Explanation: (1, 2, 4) and (2, 4, 5) are arithmetic triplets.

arithmeticTriplets([4,5,6,7,8,9], 2)
// Output: 2
// Explanation: (0, 2, 4) and (1, 3, 5) are arithmetic triplets.``````

Constraints:

• `3 <= nums.length <= 200`
• `0 <= nums[i] <= 200`
• `1 <= diff <= 50`
• `nums` is strictly increasing.

To help you get started with this lab, the initial file system for the user has been provided below. Make sure to export the function `arithmeticTriplets`.

``````/**
* @param {number[]} nums
* @param {number} diff
* @return {number}
*/
export const arithmeticTriplets = function(nums, diff) {

};``````
``````{
"name": "codedamn-lab",
"type": "module"
}``````
``````tabs: ['index.js']
terminals: ['yarn install']``````