Compilare: user.cpp: In function ‘void build_pref(const string&, std::vector<int>&)’: user.cpp:16:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<s.size();++i){ ^ user.cpp: In function ‘void kmp(const string&, const string&, int&, std::list<int>&)’: user.cpp:37:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();++i){ ^ user.cpp:41:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(q==pat.size()){ ^