Longest Palindromic Subsequence - Dynamic programming

Problem:

 Given a sequence, find the length of the longest palindromic subsequence in it. For example, if the given sequence is “BBABCBCAB”, then the output should be 7 as “BABCBAB” is the longest palindromic subseuqnce in it.“BBBBB” and “BBCBB” are also palindromic subsequences of the given sequence, but not the longest ones.

 Solution: 

class LPS
{
    // A utility function to get max of two integers
    static int max (int x, int y) { return (x > y)? x : y; }
      
    // Returns the length of the longest palindromic subsequence in seq
    static int lps(String seq)
    {
       int n = seq.length();
       int i, j, cl;
       int L[][] = new int[n][n];  // Create a table to store results of subproblems
      
       // Strings of length 1 are palindrome of lentgh 1
       for (i = 0; i < n; i++)
           L[i][i] = 1;
              
        // Build the table. Note that the lower diagonal values of table are
        // useless and not filled in the process. The values are filled in a
        // manner similar to Matrix Chain Multiplication DP solution (See
        // http://www.geeksforgeeks.org/archives/15553). cl is length of
        // substring
        for (cl=2; cl<=n; cl++)
        {
            for (i=0; i<n-cl+1; i++)
            {
                j = i+cl-1;
                if (seq.charAt(i) == seq.charAt(j) && cl == 2)
                   L[i][j] = 2;
                else if (seq.charAt(i) == seq.charAt(j))
                   L[i][j] = L[i+1][j-1] + 2;
                else
                   L[i][j] = max(L[i][j-1], L[i+1][j]);
            }
        }
              
        return L[0][n-1];
    }
          
    /* Driver program to test above functions */
    public static void main(String args[])
    {
        String seq = "GEEKSFORGEEKS";
        int n = seq.length();
        System.out.println("The lnegth of the lps is "+ lps(seq));
    }
}

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