text: Initialising the dp array to - 1
code: for ( int i = 0 ; i < dp . length ; i ++ ) for ( int j = 0 ; j < dp [ 0 ] . length ; j ++ ) for ( int k = 0 ; k < dp [ j ] [ 0 ] . length ; k ++ ) dp [ i ] [ j ] [ k ] = - 1 ;