Count Inversions Problem Statement

Given an integer array ARR of size N containing all distinct values, determine the total number of inversions present in the array.

An inversion is defined for a pair of integers in the array when the following two conditions are met:

• ARR[i] > ARR[j]
• i < j

Here, i and j are the indices ranging from [0, N).

Input:

N
ARR[0], ARR[1], ..., ARR[N-1]

Output:

Single integer indicating the total count of inversions in the array.

Example:

Input:

5
2 3 8 6 1

Output:

5

Explanation:

The inversions are: (2, 1), (3, 1), (8, 6), (8, 1), (6, 1).

Constraints:

• 1 ≤ N ≤ 105
• 1 ≤ ARR[i] ≤ 109
• ARR[i] denotes the array element at index i.

Note:

You are not required to print anything; it has already been taken care of. Just implement the given function.