Compilare: user.cpp: In function ‘std::vector<int> compute_prefix(const string&)’: user.cpp:10:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < str.size(); ++i) ^ user.cpp: In function ‘void match(const string&, const string&)’: user.cpp:27:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < text.size(); ++i) { ^ user.cpp:28:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (matched_index == str.size()) { ^