View algorithms on Arrays

Always make sure that we understand the problem statement first. There is an array of integers nums and we need to determine the number of good pairs. A pair (i , j ) is said to be good, if nums[i] == nums[j] and i < j. We need to determine how many pairs can we form that hold this condition. Let us look at some sample test cases: Input: nums = [ 1 , 2 , 3 , 1 , 1 , 3 ]Output: 4Explanation:There are 4 good pairs. (0…