Count Substrings That Satisfy K-Constraint I - Solution & Explanation

In this approach, we check all possible substrings of the given binary string s. For each substring, we count the number of 0's and 1's, then check if the substring satisfies the k-constraint. This method is straightforward but may be inefficient for longer strings.

This solution iterates through each possible starting index of a substring, then extends the substring as long as it satisfies the k-constraint. If either the number of 0's or 1's exceeds k, we stop extending the substring from that starting index.

This approach utilizes a sliding window technique to optimize counting of valid substrings. We maintain two sliding windows – one for tracking substrings with zeros ≤ k and one for substrings with ones ≤ k. The aim is to adjust the window such that it remains valid and count all substrings possible within each window.

This solution employs a function helper to count valid substrings where either '0' or '1' is ≤ k. It uses a sliding window to adjust the window size dynamically and count all possible substrings within that valid window.