/in/foo.cc: In function 'int main()':
/in/foo.cc:12:22: error: 'print' was not declared in this scope
print(zhongxu, houxu);
^
/in/foo.cc: In function 'void print(std::__cxx11::string, std::__cxx11::string)':
/in/foo.cc:28:23: error: 'std::__cxx11::string {aka class std::__cxx11::basic_string<char>}' has no member named 'substring'; did you mean 'substr'?
string a = zhongxu.substring(0, i);
^~~~~~~~~
/in/foo.cc:29:21: error: 'std::__cxx11::string {aka class std::__cxx11::basic_string<char>}' has no member named 'substring'; did you mean 'substr'?
string b = houxu.substring(0, i);
^~~~~~~~~
/in/foo.cc:32:16: error: 'std::__cxx11::string {aka class std::__cxx11::basic_string<char>}' has no member named 'substring'; did you mean 'substr'?
a = zhongxu.substring(i + 1, length - i - 1);
^~~~~~~~~
/in/foo.cc:33:14: error: 'std::__cxx11::string {aka class std::__cxx11::basic_string<char>}' has no member named 'substring'; did you mean 'substr'?
b = houxu.substring(i, length - i - 1);
^~~~~~~~~