View Compilation Error

0_0_31493028_13975.cpp: In function 'int main()':
0_0_31493028_13975.cpp:5:16: error: 'scanf' was not declared in this scope
  scanf("%d", &T);
                ^
0_0_31493028_13975.cpp:13:21: error: 'printf' was not declared in this scope
     printf("%d\n", i);
                     ^