JuniorString
Find Special Substring of Length K
You are given a string s and an integer k.
Determine if there exists a substring of length exactly k in s that satisfies the following conditions:
- The substring consists of only one distinct character.
- If there is a character immediately before the substring, it must be different from the character in the substring.
- If there is a character immediately after the substring, it must also be different from the character in the substring.
Return true if such a substring exists. Otherwise, return false.
Example 1
Input
s = "aaabaaa", k = 3Output
trueThe substring
s[4..6] == "aaa" has length 3, all characters are the same, the character before it is different, and there is no character after it.Example 2
Input
s = "abc", k = 2Output
falseThere is no substring of length 2 that consists of one distinct character and satisfies the conditions.
Constraints
- 1 <= k <= s.length <= 100
- s consists of lowercase English letters only.