View Compilation Error

0_0_31373753_15874.cpp: In function 'int main()':
0_0_31373753_15874.cpp:11:22: error: 'scanf' was not declared in this scope
  while(~scanf("%d",&t)){
                      ^
0_0_31373753_15874.cpp:15:27: error: 'printf' was not declared in this scope
    printf("%lld\n", arr[n]);
                           ^