Compilare: user.cpp: In function ‘std::vector<int> str_match(const string&, const string&)’: user.cpp:25:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < P.length(); i++) ^ user.cpp:35:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = P.length(); i < T.length(); i++) ^ user.cpp: In function ‘int main(int, char**)’: user.cpp:57:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < ans.size(); i++) ^