static void combinationUtil ( int arr [ ] , int data [ ] , int start , int end , int index , int r ) {
  if ( index == r ) {
    for ( int j = 0 ;
    j < r ;
    j ++ ) System . out . print ( data [ j ] + " " ) ;
    System . out . println ( "" ) ;
    return ;
  }
  for ( int i = start ;
  i <= end && end - i + 1 >= r - index ;
  i ++ ) {
    data [ index ] = arr [ i ] ;
    combinationUtil ( arr , data , i + 1 , end , index + 1 , r ) ;
  }
}

static void combinationUtil ( int arr [ ] , int data [ ] , int start , int end , int index , int r ) { if ( index == r ) { for ( int j = 0 ; j < r ; j ++ ) System . out . print ( data [ j ] + " ▁ " ) ; System . out . println ( " " ) ; return ; } for ( int i = start ; i <= end && end - i + 1 >= r - index ; i ++ ) { data [ index ] = arr [ i ] ; combinationUtil ( arr , data , i + 1 , end , index + 1 , r ) ; } }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (integral_type) name: (identifier) dimensions: (dimensions)) (formal_parameter type: (integral_type) name: (identifier) dimensions: (dimensions)) (formal_parameter type: (integral_type) name: (identifier)) (formal_parameter type: (integral_type) name: (identifier)) (formal_parameter type: (integral_type) name: (identifier)) (formal_parameter type: (integral_type) name: (identifier))) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (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: (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 (string_literal)))) (return_statement))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (identifier))) condition: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (binary_expression left: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (decimal_integer_literal)) right: (binary_expression left: (identifier) right: (identifier)))) update: (update_expression (identifier)) body: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (array_access array: (identifier) index: (identifier)))) (expression_statement (method_invocation name: (identifier) arguments: (argument_list (identifier) (identifier) (binary_expression left: (identifier) right: (decimal_integer_literal)) (identifier) (binary_expression left: (identifier) right: (decimal_integer_literal)) (identifier))))))))