Suppose that a C array has been declared as follows int a345

Suppose that a C++ array has been declared as follows:

int a[3][4][5];

(a) Give the access function for this array, assuming that the address of a is 1020

and int values occupy four bytes.

(b) What is the address of a[1][2][3]?

Solution

(a). The access function for this array is:

1020 + (i*20 + j*5 + k) * 4

(b). The address of a[1][2][3] is: 1020 + (1*20 + 2*5 + 3) * 4 = 1020 + (20 + 10 + 3) * 4 = 1020 + 33 * 4 = 1020 + 132 = 1052 is the address for the index: a[1][2][3].