View Compilation Error

0_0_33462550_13576.cpp: In function 'void init()':
0_0_33462550_13576.cpp:24:33: error: 'memset' was not declared in this scope
     memset(visit,0,sizeof(visit));
                                 ^
0_0_33462550_13576.cpp: In function 'void dijkstra()':
0_0_33462550_13576.cpp:30:5: error: 'priority_queue' was not declared in this scope
     priority_queue<Node>que;
     ^
0_0_33462550_13576.cpp:30:24: error: expected primary-expression before '>' token
     priority_queue<Node>que;
                        ^
0_0_33462550_13576.cpp:30:25: error: 'que' was not declared in this scope
     priority_queue<Node>que;
                         ^
0_0_33462550_13576.cpp: In function 'int main()':
0_0_33462550_13576.cpp:58:29: error: 'memset' was not declared in this scope
         memset(G,0,sizeof(G));
                             ^
0_0_33462550_13576.cpp:73:29: error: 'max' was not declared in this scope
             ans=max(ans,d[n]);
                             ^