https://leetcode.com/problems/number-of-good-pairs/

Source

    int numIdenticalPairs(vector<int>& nums) {
        const int N = nums.size();
        int cnt = 0;
        FOR (i, N) {
            const int selected = nums[i];
            FOR_INC (j, i+1, N) {
                if (selected == nums[j]) {
                    cnt++;
                }
            }
        }
        return cnt;
    }

GitHub

• NumberGoodPairs