Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:21:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0; j<a[i].size(); j++) ^ user.cpp: In function ‘int main()’: user.cpp:57:38: warning: overflow in implicit constant conversion [-Woverflow] for (j=1; j<=n; j++) dist[i][j]=oo; ^ user.cpp:69:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<a[x].size(); i++) ^ user.cpp:87:7: warning: overflow in implicit constant conversion [-Woverflow] di=oo; ^