static void printSubsequences ( int n ) {
  int opsize = ( int ) Math . pow ( 2 , n ) ;
  for ( int counter = 1 ;
  counter < opsize ;
  counter ++ ) {
    for ( int j = 0 ;
    j < n ;
    j ++ ) {
      if ( BigInteger . valueOf ( counter ) . testBit ( j ) ) System . out . print ( arr [ j ] + " " ) ;
    }
    System . out . println ( ) ;
  }
}

static void printSubsequences ( int n ) { int opsize = ( int ) Math . pow ( 2 , n ) ; for ( int counter = 1 ; counter < opsize ; counter ++ ) { for ( int j = 0 ; j < n ; j ++ ) { if ( BigInteger . valueOf ( counter ) . testBit ( j ) ) System . out . print ( arr [ j ] + " ▁ " ) ; } System . out . println ( ) ; } }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (integral_type) name: (identifier))) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (cast_expression type: (integral_type) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (decimal_integer_literal) (identifier)))))) (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))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (method_invocation object: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))) name: (identifier) arguments: (argument_list (identifier)))) consequence: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (string_literal)))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list)))))))