View Compilation Error

0_0_38165514_6754.cpp: In function 'int main()':
0_0_38165514_6754.cpp:6:15: error: 'scanf' was not declared in this scope
  scanf("%d",&n);
               ^
0_0_38165514_6754.cpp:11:22: error: 'printf' was not declared in this scope
      printf("%d ",num);
                      ^
0_0_38165514_6754.cpp:34:43: error: 'printf' was not declared in this scope
       printf("No number can be output !\n");
                                           ^