Number of Good Pairs

Easy

Given an array nums, a pair (i, j) is 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

Example 2

Input:  nums = [1,1,1,1]
Output: 6

Constraints

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