Given an array of integers A and an integer B.
Find the total number of subarrays having sum equals to B.
The first argument given is the integer array A. The second argument given is integer B.
Return the total number of subarrays having sum equals to B.
1 <= length of the array <= 50000 -1000 <= A[i] <= 1000
Input 1: A = [1, 0, 1] B = 1 Output 1: 4 Explanation 1: , [1, 0], [0, 1] and  are four subarrays having sum 1. Input 2: A = [0, 0, 0] B = 0 Output 2: 6
NOTE: You only need to implement the given function. Do not read input, instead use the arguments to the function. Do not print the output, instead return values as specified. Still have a doubt? Checkout Sample Codes for more details.