Compilare: user.cpp: In function ‘void gen_pref(std::__cxx11::string)’: user.cpp:24:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1; i<s.size(); i++) ^ user.cpp: In function ‘void solve(std::__cxx11::string, std::__cxx11::string)’: user.cpp:63:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<t.size(); i++) ^ user.cpp:67:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j==p.size()-1) ^ user.cpp: In function ‘int main()’: user.cpp:100:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<res.size(); i++) ^