Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:30:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<v[nod].size(); j++) ~^~~~~~~~~~~~~~ user.cpp: In function ‘void inv_dfs(int)’: user.cpp:41:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<vt[nod].size(); j++) ~^~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:62:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^