combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:44:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
44 | if (res1 == 0 + pref.length()){
| ~~~~~^~~~~~~~~~~~~~~~~~~~
combo.cpp:48:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
48 | if (res1 == 1 + pref.length()) second_query = pref + mp[3];
| ~~~~~^~~~~~~~~~~~~~~~~~~~
combo.cpp:51:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
51 | if (res2 == 0 + pref.length()){
| ~~~~~^~~~~~~~~~~~~~~~~~~~
combo.cpp:52:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
52 | pref += (res1 == 1 + pref.length() ? mp[2] : mp[4]);
| ~~~~~^~~~~~~~~~~~~~~~~~~~
combo.cpp:53:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
53 | }else if (res2 == 1 + pref.length()){
| ~~~~~^~~~~~~~~~~~~~~~~~~~
combo.cpp:54:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
54 | pref += (res1 == 1 + pref.length() ? mp[5] : mp[1]);
| ~~~~~^~~~~~~~~~~~~~~~~~~~
combo.cpp:56:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
56 | pref += (res1 == 1 + pref.length() ? mp[3] : mp[0]);
| ~~~~~^~~~~~~~~~~~~~~~~~~~
combo.cpp:61:20: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
61 | if (pref.length() == n) return pref;
| ~~~~~~~~~~~~~~^~~~
combo.cpp:68:33: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
68 | else if (press(pref + opt[i]) > pref.length()){
| ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~