Also provide methods used to get each answer.

3. (30 points): Merge-sort and quick-sort are two advanced sorting algorithms which can obtain an average running time complexity of O(n logn). Usually, the actual sorting time depends on the way the elements arranged themselves (We assume the sorting is in an ascending order in this question) Counting the inversions in an array is a way to measure the order. An inversion is a pair of elements (ai, aj) such that i