View Compilation Error

0_0_23196597_20284.cpp: In function 'int main()':
0_0_23196597_20284.cpp:10:25: error: 'scanf' was not declared in this scope
     while(~scanf("%d",&n))
                         ^
0_0_23196597_20284.cpp:19:24: error: 'printf' was not declared in this scope
         printf("%d\n",a);
                        ^