Compilare: main.cpp: In function 'void insert(trie*, std::string&, int)': main.cpp:61:13: 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 (idx == s.size()) { | ~~~~^~~~~~~~~~~ main.cpp: In function 'bool remove(trie*, std::string&, int)': main.cpp:73:13: 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 (idx == s.size()) { | ~~~~^~~~~~~~~~~ main.cpp: In function 'int count(trie*, std::string&, int)': main.cpp:89:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 89 | if (idx == s.size()) return now->count; | ~~~~^~~~~~~~~~~ main.cpp: In function 'int pref(trie*, std::string&, int, int)': main.cpp:94:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 94 | if (idx == s.size() || now->son[s[idx] - 'a'] == NULL) return depth; | ~~~~^~~~~~~~~~~