1512. Number of Good Pairs.c

/* 1512. 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.
 * 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
 */

int numIdenticalPairs(int* nums, int numsSize){
    int good_pairs = 0;                  // 計算好的配對總數
    for (int i = 0; i < numsSize; i++) {
        for (int j = i + 1; j < numsSize; j++) {  // 確保j必定小於i
            if (nums[i] == nums[j]) {
                good_pairs++;
            }
        }
    }
    return good_pairs;
}