Compilare: user.cpp: In function ‘void solve(int, std::string)’: user.cpp:20:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < x.size(); ++i){ ^ user.cpp:45:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < ans1.size(); ++i){ ^ user.cpp:51:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < ans2.size(); ++i){ ^