Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:11:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[x].size();j++) ^ user.cpp: In function ‘int main()’: user.cpp:27:7: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(d[i]==0)if(x==0)x=i; ^