Consider the following code int a; int *aPtr; a=9; aPtr = &a; printf ("a is equal to %d ", a); printf("the address of a is: plan", &a); print ("Using the pointer, a is equal to %d ", *aPtr); printf("Using the pointer, the address of a is: %p ", aPtr); return 0; adding functions to the above to calculate a* a and return the value: one function doing call-by value and the other function doing call by reference