Longest Palindromic Subsequence
Given a string s, find the length of the longest palindromic subsequence in s.
A subsequence is a sequence that can be derived from another sequence by deleting some or no elements without changing the order of the remaining elements.
Example 1
Input
s = "bbbab"Output
4One possible longest palindromic subsequence is "bbbb".
Example 2
Input
s = "cbbd"Output
2One possible longest palindromic subsequence is "bb".
Constraints
- 1 <= s.length <= 1000
- s consists only of lowercase English letters.