View Compilation Error

0_0_30033828_7693.cpp: In function 'int main()':
0_0_30033828_7693.cpp:51:25: error: 'scanf' was not declared in this scope
     while(scanf("%d", &n) > 0){
                         ^
0_0_30033828_7693.cpp:52:32: error: 'printf' was not declared in this scope
         printf("%lld\n", res[n]);
                                ^