Given an array A, find the number of ways to split the array into three subarrays A1, A2, A3 such that their sums are S1, S2, S3 and S2 <= S1 + S3. Subarray can only have contiguous elements. Each subarray must have atleast 1 element. If no such split is possible, return 0.

Example - 1:
A = [1,2,3,4]
Output: 2
Details: A can be broken down into 3 subarrays as follows:
- Option 1: A1 = [1], A2 = [2,3], A3 = [4]. Here S1 = 1, S2 = 5, S3 = 4 --> Hence S2 <= S1 + S3
- Option 2: A1 = [1,2], A2 = [3], A3 = [4]. Here S1 = 3, S2 = 3, S3 = 4 --> Hence S2 <= S1 + S3

Example - 2:
A = [4,20,5]
Output: 0
Details: Not possible to split A into three subarrays as per given requirement