Compilare: user.cpp: In function ‘void dfs1(int)’: user.cpp:20:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[nod].size();++i) ^ user.cpp: In function ‘int dfs2()’: user.cpp:29:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(ar2.size()<n) ^ user.cpp:37:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<v[ar2[i]].size();++j) ^