Compilare: main.cpp: In function 'void ad(trie*, int)': main.cpp:22:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 22 | if (pos == str.size() - 1) { | ~~~~^~~~~~~~~~~~~~~~~ main.cpp:30:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 30 | if (pos < str.size() && str[pos] >='a' && str[pos] <= 'z') { | ~~~~^~~~~~~~~~~~ main.cpp:36:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 36 | if ((pos < str.size() - 1)) { | ~~~~^~~~~~~~~~~~~~~~ main.cpp: In function 'bool del(trie*, int)': main.cpp:42:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 42 | if (pos <= str.size() - 1 && str[pos] >= 'a' && str[pos] <= 'z') { | ~~~~^~~~~~~~~~~~~~~~~ main.cpp:48:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 48 | if (pos == str.size()) { | ~~~~^~~~~~~~~~~~~ main.cpp: In function 'void fi(trie*, int)': main.cpp:58:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 58 | if (pos == str.size()) { | ~~~~^~~~~~~~~~~~~ main.cpp:62:11: 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 < str.size() && str[pos] >= 'a' && str[pos] <= 'z') { | ~~~~^~~~~~~~~~~~ main.cpp: In function 'void pre(trie*, int)': main.cpp:74:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 74 | if (pos < str.size() && str[pos] >= 'a' && str[pos] <= 'z') { | ~~~~^~~~~~~~~~~~