Compilare: main.cpp: In function 'void add(std::string, std::vector<nod>&)': main.cpp:21:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 21 | for ( int i = 0 ; i < s.size() ; i ++ ) | ~~^~~~~~~~~~ main.cpp: In function 'int cauta(std::string, std::vector<nod>&)': main.cpp:44:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 44 | for (int i = 0 ; i < s.size() ; i ++ ) | ~~^~~~~~~~~~ main.cpp: In function 'void sterg(std::string, std::vector<nod>&)': main.cpp:65:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 65 | for ( int i = 0 ; i < s.size() ; i ++ ) | ~~^~~~~~~~~~ main.cpp: In function 'int prefix(std::string, std::vector<nod>&)': main.cpp:80:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 80 | for ( int i = 0 ; i < s.size() ; i ++ ) | ~~^~~~~~~~~~