combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:24:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
24 | if(ret==ans.length()+2) ans+=ch[0];
| ~~~^~~~~~~~~~~~~~~~
combo.cpp:25:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
25 | else if(ret==ans.length()+1) ans+=ch[1];
| ~~~^~~~~~~~~~~~~~~~