View Compilation Error

0_0_20523663_32244.cpp:40:1: error: 'vector' does not name a type
 vector<Node> adj[N];
 ^
0_0_20523663_32244.cpp: In function 'void Prime()':
0_0_20523663_32244.cpp:73:23: error: 'adj' was not declared in this scope
   for (int j = 0; j < adj[u].size(); j++)
                       ^
0_0_20523663_32244.cpp: In function 'int main()':
0_0_20523663_32244.cpp:105:6: error: 'adj' was not declared in this scope
      adj[j].push_back(tmp1);
      ^
0_0_20523663_32244.cpp:128:5: error: 'adj' was not declared in this scope
     adj[i].clear();
     ^