A subsequence of a string s is considered a good palindromic subsequence if:
- It is a subsequence of
s. - It is a palindrome (has the same value if reversed).
- It has an even length.
- No two consecutive characters are equal, except the two middle ones.
For example, if s = "abcabcabb", then "abba" is considered a good palindromic subsequence, while "bcb" (not even length) and "bbbb" (has equal consecutive characters) are not.
Given a string s, return the length of the longest good palindromic subsequence in s.
Example 1:
Input: s = "bbabab" Output: 4 Explanation: The longest good palindromic subsequence of s is "baab".
Example 2:
Input: s = "dcbccacdb" Output: 4 Explanation: The longest good palindromic subsequence of s is "dccd".
Constraints:
1 <= s.length <= 250sconsists of lowercase English letters.