Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:19:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k=0; k<a[u].size(); k++) ^ user.cpp: In function ‘void dfst(int)’: user.cpp:33:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k=0; k<at[u].size(); k++) ^ user.cpp: In function ‘int main()’: user.cpp:45:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,x,y; ^