2176. Count Equal and Divisible Pairs in an Array

class Solution {
public:
    int countPairs(vector<int>& nums, int k) {
        int ans = 0;
        for (int i = 0; i < nums.size(); i++) {
            for (int j = i + 1; j < nums.size(); j++) {
                if (nums[i] == nums[j] && (i * j) % k == 0) {
                    ans++;
                }
            }
        }
        return ans;
    }
};