Given a binary string s (a string consisting only of '0's and '1's), we
can split s into 3 non-empty strings s1, s2, s3 (s1+
s2+ s3 = s).
Return the number of ways s can be split such that the number of characters
'1' is the same in s1, s2, and s3.
Since the answer may be too large, return it modulo 10^9 + 7.
Example 1:
Input: s = "10101" Output: 4 Explanation: There are four ways to split s in 3 parts where each part contain the same number of letters '1'. "1|010|1" "1|01|01" "10|10|1" "10|1|01"
Example 2:
Input: s = "1001" Output: 0
Example 3:
Input: s = "0000" Output: 3 Explanation: There are three ways to split s in 3 parts. "0|0|00" "0|00|0" "00|0|0"
Example 4:
Input: s = "100100010100110" Output: 12
Constraints:
s[i] == '0' or s[i] == '1'3 <= s.length <= 10^5