Compilare: main.cpp: In function 'void adds(nod*, int)': main.cpp:25:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 25 | if (pos==w.size()) { | ~~~^~~~~~~~~~ main.cpp: In function 'void deletes(nod*, int)': main.cpp:47:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 47 | if (pos==w.size()) { | ~~~^~~~~~~~~~ main.cpp: In function 'int appears(nod*, int)': main.cpp:61:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 61 | if (pos==w.size()) return x->nr_ap; | ~~~^~~~~~~~~~ main.cpp: In function 'int common_prefix(nod*, int)': main.cpp:69:46: 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 (x->fiu[w[pos]-'a'] == nullptr || pos == w.size()) { | ~~~~^~~~~~~~~~~