Compilare: main.cpp: In instantiation of 'void AhoCorasick<NodeType>::insert(const string&, int) [with NodeType = trie_node; std::__cxx11::string = std::__cxx11::basic_string<char>]': main.cpp:90:42: required from here main.cpp:66:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0, son=0; i<str.size(); ++i, ptr = ptr->sons[son]) { ~^~~~~~~~~~~ main.cpp: In instantiation of 'void AhoCorasick<NodeType>::Compute(int*) [with NodeType = trie_node]': main.cpp:95:21: required from here main.cpp:46:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0, son; i<Str.size(); ++i) { ~^~~~~~~~~~~