combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:18:23: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
18 | while (res.size() < N){
| ~~~~~~~~~~~^~~
combo.cpp:20:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
20 | if (ans == res.size()) res += lchars[2];
| ~~~~^~~~~~~~~~~~~
combo.cpp:21:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
21 | if (ans == res.size() + 1) {
| ~~~~^~~~~~~~~~~~~~~~~
combo.cpp:23:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
23 | if (sans == res.size()) res += lchars[0] + lchars[2];
| ~~~~~^~~~~~~~~~~~~
combo.cpp:24:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
24 | if (sans == res.size() + 1) res += lchars[1] + lchars[2];
| ~~~~~^~~~~~~~~~~~~~~~~
combo.cpp:29:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
29 | if (sans == res.size()) res += lchars[1] + lchars[0];
| ~~~~~^~~~~~~~~~~~~
combo.cpp:30:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
30 | if (sans == res.size() + 1) res += lchars[0] + lchars[1];
| ~~~~~^~~~~~~~~~~~~~~~~
combo.cpp:17:81: warning: offset '97' outside bounds of constant string [-Warray-bounds]
17 | for (auto c : {'a', 'b', 'x', 'y'}) if (c != res[0]) lchars.push_back("" + c);
| ^
combo.cpp:17:81: warning: offset '97' outside bounds of constant string [-Warray-bounds]