Here are three fragments of code. Assume that integer variables have been declared already, and that sum is initialized somewhere to zero.

/* loop 1 */

for( j = 1; j < 20; j *= 2 )

sum += j;

/* loop 2 */

for( j = 16; j; j /= 2 )

sum = sum + j;

/* loop 3 */

j = 1;

while ( j < 16 )

{

sum += j;

j *= 2;

}

The loops 1, 2, and 3 set sum to:

15, 15, 31

31, 31, 15

32, 32, 32

31, 31, 31

32, 32, 16