static boolean isPrefix ( String str , int len , int i , int k ) {
  if ( i + k > len ) return false ;
  for ( int j = 0 ;
  j < k ;
  j ++ ) {
    if ( str . charAt ( i ) != str . charAt ( j ) ) return false ;
    i ++ ;
  }
  return true ;
}

static boolean isPrefix ( String str , int len , int i , int k ) { if ( i + k > len ) return false ; for ( int j = 0 ; j < k ; j ++ ) { if ( str . charAt ( i ) != str . charAt ( j ) ) return false ; i ++ ; } return true ; }
(method_declaration (modifiers) type: (boolean_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (type_identifier) 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: (binary_expression left: (identifier) right: (identifier)) right: (identifier))) consequence: (return_statement (false))) (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 (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: (return_statement (false))) (expression_statement (update_expression (identifier))))) (return_statement (true))))