Given a binary array, find the total number of subarrays with the ratio of 0's and 1's equal to x:y.

Constraints:

n = arr.length

2<=n<=1e5

1<=x,y<=n

Example: arr = [0,1,0,1] x = 1 y = 1

Output: 4

Explanation: The four possible subarrays are as follows:

[0 1] 0 1 --> [0,1]

0 [1 0] 1 --> [1,0]

0 1 [0 1] --> [0,1]

[0 1 0 1] --> [0,1,0,1]

With the given constraints, expecting solution no worse than O(n)

P.s: Maybe the problem can be solved using the sliding window technique. But unable to apply it due to ratio constraint.