View Compilation Error

0_0_22328638_5430.cpp: In function 'int main()':
0_0_22328638_5430.cpp:37:24: error: 'scanf' was not declared in this scope
     while(scanf("%d",&n)!=EOF&&n)
                        ^
0_0_22328638_5430.cpp:37:27: error: 'EOF' was not declared in this scope
     while(scanf("%d",&n)!=EOF&&n)
                           ^
0_0_22328638_5430.cpp:48:33: error: 'sort' was not declared in this scope
         sort(node+1,node+1+m,cmp);
                                 ^
0_0_22328638_5430.cpp:50:26: error: 'printf' was not declared in this scope
         printf("%d\n",sum);
                          ^