Given an unsorted array arr[] of N integers and a sum. The task is to count the number of subarrays which add to a given number.

Example 1:
Input:
N=5
sum=-10
arr[] = { 10, 2, -2, -20, 10 }
Output: 3
Explanation:
Subarrays with sum -10 are:
[10, 2, -2, -20], [2, -2, -20, 10]
and [-20, 10].

Example 2:
Input:
N=6
sum= 33
arr[] = { 1, 4, 20, 3, 10, 5 }
Output: 1
Your Task:
Since, this is a function problem. You don't need to take any input, as it is already accomplished by the driver code. You just need to complete the function subArraySum() that takes array arr , integer N and integer sum as parameters and returns the count of the subarray which adds to the given sum.

Expected Time Complexity: O(N).
Expected Auxiliary Space: O(N).

Constraints:
1 ≤ N ≤ 10^{6}

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