How do you do this question and why is the answer D?

D. (while i>=2 && lessthan(item, items.get(i/2))

{

       items.set(i, items.set(i/2);

       i /= 2;

}

Explanation:

This is a heap data structure.

Heap can be like:

                                 0

                           1          2

                       3     4     5  

 which is represented in list as = [0,1,2,3,4,5]

Hence, heap is a tree type of data structure.

// repairs the heap by moving the last leaf to the right place.

private reheapUp()

{

         int i =items.size()-1;// index of last leaf

         Object temp = items.get(i);

(while i>=2 && lessthan(temp, items.get(i/2))

{

       items.set(i, items.get(i/2);

       i /= 2;

}

  items.set(i, temp);

}

And seeing the structure of heap tree data structure, the D option as mentioned above looks correct.

As i=5

Object.temp =items.get(5);

(true && lessthan(5,3))

{

      items.set(5, temp)

and temp = 5. And hence 5 is set to 5, and so on (please check next loop with i /=2 => i=2.5=3

And hence, D is the correct option for this question.