Find whether a string contains a length-k substring that satisfies a special validity condition.
Problem
Given a string s and an integer k, determine whether there exists a substring of length k that is considered special according to the problem's validity rule.
A typical approach is to inspect all length-k substrings efficiently and check whether each one satisfies the required condition without reprocessing the entire window from scratch.
Return the required result based on whether such a substring exists.
Input Format
- A string
s. - An integer
k.
The exact validity rule for a substring is determined by the problem statement.
Output Format
- Return the required value indicating whether at least one special substring of length
kexists.
Constraints
1 <= k <= |s|- String length is assumed to be within standard interview limits.
- Characters are assumed to be lowercase English letters unless stated otherwise.
Example 1
Input
s = "abcabc", k = 3
Output
true
Explanation
There is at least one length-3 substring that satisfies the condition.
Example 2
Input
s = "aaaa", k = 2
Output
false
Explanation
No substring of length 2 satisfies the required special condition.
Premium problem context
Unlock deeper context for this problem
Premium adds guided hints, editorial links, similar variants, discussion resources, and concept maps so you can understand why a problem matters, not just solve it once.