You are given a binary string s and an integer k.
A binary string satisfies the k-constraint if either of the following conditions holds:
0's in the string is at most k.1's in the string is at most k.Return an integer denoting the number of substrings of s that satisfy the k-constraint.
Example 1:
Input: s = "10101", k = 1
Output: 12
Explanation:
Every substring of s except the substrings "1010", "10101", and "0101" satisfies the k-constraint.
Example 2:
Input: s = "1010101", k = 2
Output: 25
Explanation:
Every substring of s except the substrings with a length greater than 5 satisfies the k-constraint.
Example 3:
Input: s = "11111", k = 1
Output: 15
Explanation:
All substrings of s satisfy the k-constraint.
Constraints:
1 <= s.length <= 50 1 <= k <= s.lengths[i] is either '0' or '1'."10101" 1 "1010101" 2 "11111" 1