Compilare: main.cpp: In function 'void add(Node*&, int)': main.cpp:24:12: 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(pos == s.size()) | ~~~~^~~~~~~~~~~ main.cpp:26:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 26 | if(pos < s.size()) | ~~~~^~~~~~~~~~ main.cpp: In function 'void rem(Node*&, int)': main.cpp:38:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 38 | if(pos == s.size()) | ~~~~^~~~~~~~~~~ main.cpp: In function 'void query(Node*&, int)': main.cpp:73:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 73 | if(pos < s.size()) | ~~~~^~~~~~~~~~