Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:14:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(register int i=0;i<L[nod].size();i++){ ^ user.cpp: In function ‘int main()’: user.cpp:23:20: warning: unused variable ‘j’ [-Wunused-variable] register int i,j,k,x,y; ^ user.cpp:23:22: warning: unused variable ‘k’ [-Wunused-variable] register int i,j,k,x,y; ^