Compilare: main.cpp: In function 'void add(nod*, int)': main.cpp:23:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 23 | if (pos==word.size()) { | ~~~^~~~~~~~~~~~~ main.cpp: In function 'bool pop(nod*, int)': main.cpp:35:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 35 | if (pos==word.size()) { | ~~~^~~~~~~~~~~~~ main.cpp: In function 'int count_words(nod*, int)': main.cpp:52:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 52 | if (pos==word.size()) { | ~~~^~~~~~~~~~~~~ main.cpp: In function 'int common_prefix(nod*, int)': main.cpp:62:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 62 | if (pos==word.size()) { | ~~~^~~~~~~~~~~~~