View Compilation Error

0_0_19794769_110.cpp: In function 'int main()':
0_0_19794769_110.cpp:8:5: error: 'cin' was not declared in this scope
     cin >> c;
     ^
0_0_19794769_110.cpp:12:32: error: 'printf' was not declared in this scope
         printf("%.2f%\n", 1 / n);
                                ^