Count All Palindromic Subsequence in a given String | Java code to Count Palindromic Subsequence in a given String ; Function return the total palindromic subsequence ; create a 2D array to store the count of palindromic subsequence ; palindromic subsequence of length 1 ; check subsequence of length L is palindrome or not ; return total palindromic subsequence ; Driver program
public class GFG { static int countPS ( String str ) { int N = str . length ( ) ; int [ ] [ ] cps = new int [ N ] [ N ] ; for ( int i = 0 ; i < N ; i ++ ) cps [ i ] [ i ] = 1 ; for ( int L = 2 ; L <= N ; L ++ ) { for ( int i = 0 ; i <= N - L ; i ++ ) { int k = L + i - 1 ; if ( str . charAt ( i ) == str . charAt ( k ) ) { cps [ i ] [ k ] = cps [ i ] [ k - 1 ] + cps [ i + 1 ] [ k ] + 1 ; } else { cps [ i ] [ k ] = cps [ i ] [ k - 1 ] + cps [ i + 1 ] [ k ] - cps [ i + 1 ] [ k - 1 ] ; } } } return cps [ 0 ] [ N - 1 ] ; } public static void main ( String args [ ] ) { String str = " abcb " ; System . out . println ( " Total ▁ palindromic ▁ " + " subsequence ▁ are ▁ : ▁ " + countPS ( str ) ) ; } }