View Compilation Error

0_0_22645908_11051.cpp: In function 'int main()':
0_0_22645908_11051.cpp:4:15: error: 'scanf' was not declared in this scope
  scanf("%d",&t);
               ^
0_0_22645908_11051.cpp:22:32: error: 'printf' was not declared in this scope
    if(k!=n-1) printf("%d ",a[k]);
                                ^
0_0_22645908_11051.cpp:23:25: error: 'printf' was not declared in this scope
    else printf("%d",a[k]);
                         ^
0_0_22645908_11051.cpp:25:14: error: 'printf' was not declared in this scope
   printf("\n");
              ^