Compilare: main.cpp: In function 'void add(nod*, 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==w.size()) { | ~~~^~~~~~~~~~ main.cpp: In function 'bool deletion(nod*, int)': main.cpp:37:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 37 | if (pos==w.size()) { | ~~~^~~~~~~~~~ main.cpp: In function 'int appears(nod*, int)': main.cpp:55:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 55 | if (pos==w.size()) { | ~~~^~~~~~~~~~ main.cpp: In function 'int longest_prefix(nod*, int)': main.cpp:69:42: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 69 | if (parent->fiu[w[pos]-'a']==0 || pos==w.size()) { | ~~~^~~~~~~~~~