Longest_palindromic_subsequence.java

//User function Template for Java

class Solution
{
    public int longestPalinSubseq(String S)
    {
        int n=S.length();
        int dp[][]=new int[n+1][n+1];
        String rev=new StringBuilder(S).reverse().toString();
        for(int i=n;i>=0;i--)
        {
            for(int j=n;j>=0;j--)
            {
                if(i==n || j==n)
                    dp[i][j]= 0;
                else if(S.charAt(i)==rev.charAt(j))
                    dp[i][j]=1+dp[i+1][j+1];
                else
                    dp[i][j]=Math.max(dp[i+1][j],dp[i][j+1]);
            }
        }
        return dp[0][0];
        //code here
    }
}