password.cpp: In function 'bool add(std::string)':
password.cpp:13:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
13 | return ret == str.size() + ans.size() + 1;
| ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
password.cpp: In function 'void solve(int, int)':
password.cpp:19:33: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
19 | if (ans.size() + str.size() == N) return;
| ~~~~~~~~~~~~~~~~~~~~~~~~^~~~
password.cpp: In function 'std::string guess(int, int)':
password.cpp:44:36: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
44 | while (ans.size() + str.size() < n)
| ~~~~~~~~~~~~~~~~~~~~~~~~^~~