Compilare: user.cpp: In function ‘std::vector<std::vector<int> > Solve()’: user.cpp:36:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<wh[1].size();++i) { ^ user.cpp:43:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<wh[0].size();++i){ ^