View Compilation Error

0_0_35602544_30588.cpp: In function 'int main()':
0_0_35602544_30588.cpp:6:15: error: 'scanf' was not declared in this scope
  scanf("%d",&n);
               ^
0_0_35602544_30588.cpp:7:10: error: 'getchar' was not declared in this scope
  getchar();
          ^
0_0_35602544_30588.cpp:26:26: error: 'printf' was not declared in this scope
    printf("%.2f\n",result);
                          ^
0_0_35602544_30588.cpp:28:29: error: 'printf' was not declared in this scope
    printf("%d\n",(int)result);
                             ^