Compilare: main.cpp: In function 'void insertInTrie(trieNode*, std::__cxx11::string&, int)': main.cpp:26:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos == word.size()) { ~~~~^~~~~~~~~~~~~~ main.cpp: In function 'void deleteFromTrie(trieNode*, std::__cxx11::string&, int)': main.cpp:40:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos == word.size()) { ~~~~^~~~~~~~~~~~~~ main.cpp: In function 'int printWordApparitions(trieNode*, std::__cxx11::string&, int)': main.cpp:50:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos == word.size()) { ~~~~^~~~~~~~~~~~~~ main.cpp: In function 'int longestCommonPrefix(trieNode*, std::__cxx11::string&, int)': main.cpp:62:55: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (node == NULL || node -> passingWords == 0 || pos == word.size()) { ~~~~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:71:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("trie.in", "r", stdin); ^ main.cpp:72:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("trie.out", "w", stdout); ^