combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:11:19: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
11 | while(S.length()<=N){
| ~~~~~~~~~~^~~
combo.cpp:12:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
12 | if(press(S+'A')==S.length()+1){S+='A';continue;}
| ~~~~~~~~~~~~^~~~~~~~~~~~~~
combo.cpp:13:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
13 | if(press(S+'B')==S.length()+1){S+='B';continue;}
| ~~~~~~~~~~~~^~~~~~~~~~~~~~
combo.cpp:14:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
14 | if(press(S+'X')==S.length()+1){S+='X';continue;}
| ~~~~~~~~~~~~^~~~~~~~~~~~~~
combo.cpp:15:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
15 | if(press(S+'Y')==S.length()+1){S+='Y';continue;}
| ~~~~~~~~~~~~^~~~~~~~~~~~~~
combo.cpp:9:7: warning: unused variable 'coins' [-Wunused-variable]
9 | int coins = press(p);
| ^~~~~