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