Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:21:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[x].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:100:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<speed[i].size();j++) ^ user.cpp:105:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<q[i].size();j++) ^