Number of Substrings With Only 1s
Given a binary string s, return the number of substrings with all characters 1's.
Since the answer may be too large, return it modulo 10^9 + 7.
Example 1
Input
s = "0110111"Output
9There are 9 substrings in total with only
1 characters: "1" appears 5 times, "11" appears 3 times, and "111" appears 1 time.Example 2
Input
s = "101"Output
2Substring
"1" is shown 2 times in s.Constraints
- 1 <= s.length <= 10^5
- s[i] is either '0' or '1'.