combo.cpp: In function 'char solveNext(std::string)':
combo.cpp:16:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
16 | if (res == a.length() + 1){
| ~~~~^~~~~~~~~~~~~~~~~
combo.cpp:19:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
19 | if (res == a.length() + 2){
| ~~~~^~~~~~~~~~~~~~~~~
combo.cpp:22:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
22 | if (res == a.length()){
| ~~~~^~~~~~~~~~~~~
combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:30:7: warning: unused variable 'ans1' [-Wunused-variable]
30 | char ans1;
| ^~~~