Compilare: user.cpp: In function ‘int nr_unmark(int)’: user.cpp:45:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<G[node].size();++i) ^ user.cpp: In function ‘void add(int)’: user.cpp:58:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<G[node].size();++i) ^ user.cpp:70:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<G[son].size();++j) ^ user.cpp: In function ‘void write()’: user.cpp:105:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<sol.size();++i) ^