Watch 10 video solutions for Find the Longest Semi-Repetitive Substring, a medium level problem involving String, Sliding Window. This walkthrough by NeetCode has 657,697 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
You are given a digit string s that consists of digits from 0 to 9.
A string is called semi-repetitive if there is at most one adjacent pair of the same digit. For example, "0010", "002020", "0123", "2002", and "54944" are semi-repetitive while the following are not: "00101022" (adjacent same digit pairs are 00 and 22), and "1101234883" (adjacent same digit pairs are 11 and 88).
Return the length of the longest semi-repetitive substring of s.
Example 1:
Input: s = "52233"
Output: 4
Explanation:
The longest semi-repetitive substring is "5223". Picking the whole string "52233" has two adjacent same digit pairs 22 and 33, but at most one is allowed.
Example 2:
Input: s = "5494"
Output: 4
Explanation:
s is a semi-repetitive string.
Example 3:
Input: s = "1111111"
Output: 2
Explanation:
The longest semi-repetitive substring is "11". Picking the substring "111" has two adjacent same digit pairs, but at most one is allowed.
Constraints:
1 <= s.length <= 50'0' <= s[i] <= '9'