combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:48:28: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
48 | while (prefix.length() < N)
| ~~~~~~~~~~~~~~~~^~~
combo.cpp:60:59: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
60 | while (query_string.length() + s.length() + 1 < N * 4)
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
combo.cpp:66:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
66 | if (n > prefix.length())
| ~~^~~~~~~~~~~~~~~~~
combo.cpp:68:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
68 | if (n < s.length())
| ~~^~~~~~~~~~~~
combo.cpp:10:10: warning: unused variable 'first_char' [-Wunused-variable]
10 | char first_char;
| ^~~~~~~~~~