Write a program in pseudocode to solve this problem. You may use any program presented in class without writing it as part of your answer. The input is a list of n integers, some of which may be equal. The output is the number m of pairs of equal input numbers. For example, if the input list is 3 1 5 1 2 1 2 1, then the output is m = 7 because there are six pairs (1,1) and one pair (2,2) in the input. (There are four 1s. Six is 4 choose 2, the number of pairs you can form from 4 things.) Full credit for a O(n log n) solution. Half credit for a O(n²) solution. Hint: Sort first.