Compilare: main.cpp: In function 'void build(std::string)': main.cpp:12:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 12 | while(i<q.length()){ | ~^~~~~~~~~~~ main.cpp: In function 'void solve(std::string, std::string, std::string&)': main.cpp:32:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 32 | while(i<w.length()){ | ~^~~~~~~~~~~ main.cpp:36:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 36 | if(j==q.length()){ | ~^~~~~~~~~~~~