longest-palindromic-subsequence.java

public class Solution {
    public int longestPalindromeSubseq(String s) {
        int len = s.size();
        int dp[][] = new int[len][len];
        for (int i = len-1; i >= 0; i--) {
            dp[i][i] = 1;
            for (int j = i+1; j < len; j++) {
                if (s.charAt(i) == s.charAt(j)) dp[i][j] = dp[i+1][j-1] + 2;
                else {
                    dp[i][j] = Math.max(dp[i][j-1], dp[i+1][j]);
                }
            }
        }
        return dp[0][len-1];
    }
}