combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:37:24: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
37 | while ( ans.size() < N ){
| ~~~~~~~~~~~^~~
combo.cpp:40:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
40 | if ( p == ans.size() + 2 ){
| ~~^~~~~~~~~~~~~~~~~
combo.cpp:42:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
42 | } else if ( p == ans.size() + 1 ){
| ~~^~~~~~~~~~~~~~~~~
combo.cpp:28:9: warning: variable 'ch' set but not used [-Wunused-but-set-variable]
28 | int ch;
| ^~