View Compilation Error

0_0_34178108_23163.cpp: In function 'int main()':
0_0_34178108_23163.cpp:8:15: error: 'scanf' was not declared in this scope
  scanf("%d",&n);
               ^
0_0_34178108_23163.cpp:11:23: error: 'printf' was not declared in this scope
   printf("%lld",f[y-x]);
                       ^