counting inversions using divide-and-conquer algorithm
This file "IntegerArray.txt" contains all of the 100,000 integers between 1 and 100,000 (inclusive) in some order, with no integer repeated.
Your task is to compute the number of inversions in the file given, where the ithi^{th}ith row of the file indicates the ithi^{th}ith entry of an array.
Because of the large size of this array, you should implement the fast divide-and-conquer algorithm.