Compilare: user.cpp: In function ‘bool weCan(int)’: user.cpp:29:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<C.size();i++) ^ user.cpp:41:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0;j<V[C[i].first].size();j++) ^ user.cpp:31:13: warning: variable ‘ok’ set but not used [-Wunused-but-set-variable] int ok = 0; ^