Compilare: main.cpp: In function 'void print_longest_prefix(std::__cxx11::string)': main.cpp:35:37: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::__cxx11::basic_string<char>::size_type {aka long unsigned int}' [-Wformat=] printf("%d\n",word.size()); ^ main.cpp: In function 'int main()': main.cpp:45:37: 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); ^