p115.java

/*Given an array of integers nums, return the number of good pairs.

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

 

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*/

// Brute Force
class Solution {
    public int numIdenticalPairs(int[] nums) {
        int c=0;
        for(int i=0;i<nums.length;i++){
            for(int j=i+1;j<nums.length;j++){
                if(nums[i]==nums[j]){
                    if(i<j){
                        c++;
                    }
                }
            }
        }
        return c;
    }
}