1512. Number of Good Pairs

Q:

Given an array of integers nums.

A pair (i,j) is called good if nums[i] == nums[j] and i < j.

Return the number of good pairs.

 

Example 1:

Input: nums = [1,2,3,1,1,3]
Output: 4
Explanation: There are 4 good pairs (0,3), (0,4), (3,4), (2,5) 0-indexed.

Example 2:

Input: nums = [1,1,1,1]
Output: 6
Explanation: Each pair in the array are good.

Example 3:

Input: nums = [1,2,3]
Output: 0

 

Constraints:

• 1 <= nums.length <= 100
• 1 <= nums[i] <= 100

A:

class Solution {
public:
    int numIdenticalPairs(vector<int>& nums) {
        int res = 0;
        for(int i =0;i<nums.size()-1;++i){
            for(int j = i+1;j<nums.size(); ++j){
                if(nums[i] == nums[j]){
                    res++;
                }
            }
        }
        return res;
    }
};