Compilare: user.cpp: In function ‘void AddWord(Node*, int, const string&, int)’: user.cpp:23:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos == s.size()) { ^ user.cpp: In function ‘std::vector<std::vector<int> > PreRMQ(const std::vector<int>&)’: user.cpp:56:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while ((1 << log) <= e.size()) { ^ user.cpp:62:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < e.size(); ++i) { ^ user.cpp:67:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i + (1 << j) - 1 < e.size(); ++i) { ^