View Compilation Error

0_0_22319677_23901.cpp: In function 'int main()':
0_0_22319677_23901.cpp:5:41: error: 'scanf' was not declared in this scope
  while(~scanf("%c%c%c",&a[0],&a[1],&a[2]))
                                         ^
0_0_22319677_23901.cpp:7:14: error: 'getchar' was not declared in this scope
      getchar();
              ^
0_0_22319677_23901.cpp:16:37: error: 'printf' was not declared in this scope
   printf("%c %c %c\n",a[0],a[1],a[2]);
                                     ^