Given a?0-indexed?integer array?nums?of length?n?and an integer?k, return?the?number of pairs?(i, j)?where?0 <= i < j < n,?such that?nums[i] == nums[j]?and?(i * j)?is divisible by?k.

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Example 1:

Input: nums = [3,1,2,2,2,1,3], k = 2

Output: 4

Explanation:

There are 4 pairs that meet all the requirements:?

- nums[0] == nums[6], and 0 * 6 == 0, which is divisible by 2.?

- nums[2] == nums[3], and 2 * 3 == 6, which is divisible by 2.?

- nums[2] == nums[4], and 2 * 4 == 8, which is divisible by 2.?

- nums[3] == nums[4], and 3 * 4 == 12, which is divisible by 2.

Example 2:

Input: nums = [1,2,3,4], k = 1

Output: 0

Explanation: Since no value in nums is repeated, there are no pairs (i,j) that meet all the requirements.

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Constraints:

• 1 <= nums.length <= 100

• 1 <= nums[i], k <= 100

• Easy 題目，遍歷即可。

Runtime:?3 ms, faster than?99.48%?of?Java?online submissions for?Count Equal and Divisible Pairs in an Array.

Memory Usage:?42.4 MB, less than?31.63%?of?Java?online submissions for?Count Equal and Divisible Pairs in an Array.