static int minStepToDeleteString ( String str ) {
  int N = str . length ( ) ;
  int [ ] [ ] dp = new int [ N + 1 ] [ N + 1 ] ;
  for ( int i = 0 ;
  i <= N ;
  i ++ ) for ( int j = 0 ;
  j <= N ;
  j ++ ) dp [ i ] [ j ] = 0 ;
  for ( int len = 1 ;
  len <= N ;
  len ++ ) {
    for ( int i = 0 , j = len - 1 ;
    j < N ;
    i ++ , j ++ ) {
      if ( len == 1 ) dp [ i ] [ j ] = 1 ;
      else {
        dp [ i ] [ j ] = 1 + dp [ i + 1 ] [ j ] ;
        if ( str . charAt ( i ) == str . charAt ( i + 1 ) ) dp [ i ] [ j ] = Math . min ( 1 + dp [ i + 2 ] [ j ] , dp [ i ] [ j ] ) ;
        for ( int K = i + 2 ;
        K <= j ;
        K ++ ) if ( str . charAt ( i ) == str . charAt ( K ) ) dp [ i ] [ j ] = Math . min ( dp [ i + 1 ] [ K - 1 ] + dp [ K + 1 ] [ j ] , dp [ i ] [ j ] ) ;
      }
    }
  }
  return dp [ 0 ] [ N - 1 ] ;
}

static int minStepToDeleteString ( String str ) { int N = str . length ( ) ; int [ ] [ ] dp = new int [ N + 1 ] [ N + 1 ] ; for ( int i = 0 ; i <= N ; i ++ ) for ( int j = 0 ; j <= N ; j ++ ) dp [ i ] [ j ] = 0 ; for ( int len = 1 ; len <= N ; len ++ ) { for ( int i = 0 , j = len - 1 ; j < N ; i ++ , j ++ ) { if ( len == 1 ) dp [ i ] [ j ] = 1 ; else { dp [ i ] [ j ] = 1 + dp [ i + 1 ] [ j ] ; if ( str . charAt ( i ) == str . charAt ( i + 1 ) ) dp [ i ] [ j ] = Math . min ( 1 + dp [ i + 2 ] [ j ] , dp [ i ] [ j ] ) ; for ( int K = i + 2 ; K <= j ; K ++ ) if ( str . charAt ( i ) == str . charAt ( K ) ) dp [ i ] [ j ] = Math . min ( dp [ i + 1 ] [ K - 1 ] + dp [ K + 1 ] [ j ] , dp [ i ] [ j ] ) ; } } } return dp [ 0 ] [ N - 1 ] ; }
(method_declaration (modifiers) type: (integral_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (type_identifier) name: (identifier))) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (array_type element: (integral_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (binary_expression left: (identifier) right: (decimal_integer_literal))) dimensions: (dimensions_expr (binary_expression left: (identifier) right: (decimal_integer_literal)))))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (expression_statement (assignment_expression left: (array_access array: (array_access array: (identifier) index: (identifier)) index: (identifier)) right: (decimal_integer_literal))))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal)) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (identifier) right: (decimal_integer_literal)))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (expression_statement (assignment_expression left: (array_access array: (array_access array: (identifier) index: (identifier)) index: (identifier)) right: (decimal_integer_literal))) alternative: (block (expression_statement (assignment_expression left: (array_access array: (array_access array: (identifier) index: (identifier)) index: (identifier)) right: (binary_expression left: (decimal_integer_literal) right: (array_access array: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) index: (identifier))))) (if_statement condition: (parenthesized_expression (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (identifier) right: (decimal_integer_literal)))))) consequence: (expression_statement (assignment_expression left: (array_access array: (array_access array: (identifier) index: (identifier)) index: (identifier)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (decimal_integer_literal) right: (array_access array: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) index: (identifier))) (array_access array: (array_access array: (identifier) index: (identifier)) index: (identifier))))))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (identifier) right: (decimal_integer_literal)))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (if_statement condition: (parenthesized_expression (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))))) consequence: (expression_statement (assignment_expression left: (array_access array: (array_access array: (identifier) index: (identifier)) index: (identifier)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (array_access array: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (array_access array: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) index: (identifier))) (array_access array: (array_access array: (identifier) index: (identifier)) index: (identifier)))))))))))))) (return_statement (array_access array: (array_access array: (identifier) index: (decimal_integer_literal)) index: (binary_expression left: (identifier) right: (decimal_integer_literal))))))