Compilare: user.cpp: In function ‘void lee(int, int)’: user.cpp:30:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int it=0;it<a[k].size();++it) ^ user.cpp: In function ‘void dijkstra(int)’: user.cpp:69:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(it=0;it<a[x].size();++it) ^ user.cpp:82:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(x>1)for(it=0;it<a[x].size();++it) ^