[leetcode]516. Longest Palindromic Subsequence最长回文子序列

Given a string s, find the longest palindromic subsequence's length in s. You may assume that the maximum length of s is 1000.

Example 1:
Input:

"bbbab"

Output: 

4

One possible longest palindromic subsequence is "bbbb".

题意：

Solution1：

code