View Compilation Error

0_0_27588715_6957.cpp: In function 'int main()':
0_0_27588715_6957.cpp:22:15: error: 'scanf' was not declared in this scope
  scanf("%d",&t);
               ^
0_0_27588715_6957.cpp:50:20: error: 'printf' was not declared in this scope
   printf("%d\n",sum);
                    ^