(Make sure the program is in C) Given an array of N elements, you notice that there are some duplicate values. Implement a modified merge function such that the mergesort code we saw in class both sorts the array and removes all duplicates from the array. Your algorithm should run in O(N log N) time; briefly argue/justify that your program runs in O(N log N) time. Note: You are not allowed to simply call mergesort, and then remove duplicates by scanning the array after sorting it. You must modify the merge function. You may assume all elements in the original array are positive, and fill in empty spots with -1. Make sure there are no duplicate positive numbers, and as long as positive numbers are in sorted order if all -1 elements are ignored, the output would correct. You dont need to sort the -1s.