Answers
1. We have been asked about elements in list1. as in the figure, list1 contains value 0, thius means list1 starts with index [0] of nodes.
So, the first element of list1 is the element stored in .info corresponding to [0] i.e. John
.next corresponding to John contains 4, this means the next element of list is stored at index [4] i.e. Nell
.next corresponding to Nell contains 8, this means the next element of list is stored at index [8] i.e.
Susan
.next corresponding to Susan contains 9, this means the next element of list is stored at index [9] i.e. Sussane
.next corresponding to Sussane is NUL, so, list1 terminates here.
so, list1 = [John Nell Susan Sussane]
2. Similarly, we can find out elements in list2 also
the first element of list2 is the element stored in .info corresponding to [1] i.e. Mark
.next corresponding to mark contains 5, this means the next element of list is stored at index [5] i.e. Naomi
.next corresponding to Naomi contains 6, this means the next element of list is stored at index [6] i.e.
Robert
.next corresponding to Robert is NUL, so, list2 terminates here.
So, list2 = [Mark Naomi Robert]
3. free starts with 7, .next of 7 contains 2, .next of 2 contains 3 and .next of 3 is Nul
So, index 7, 2 and 3 are part of free list
4. if we delete Nell from the list1, .next of John will be replaced by .next of Nell and index of Nell will be added to free list i.e. 4 will be added to .next of index [3] and .next of index [4] will be set to NUL.
Here is final List
| node | .info | .next |
| [0] | John | 8 |
| [1] | Mark | 5 |
| [2] | 3 | |
| [3] | 4 | |
| [4] | NUL | |
| [5] | Naomi | 6 |
| [6] | Robert | NUL |
| [7] | 2 | |
| [8] | Susan | 9 |
| [9] | Sussane | NUL |
5. When we add an element to a list, it is added at the end To add a new name, we need to take a node from free, write new value to this node and set .next of the last element of list to index of this node and further set .next of index corresponding to this node to NUL.
In our case, we take the last node of the free list i.e.
3 and do the following
write Anne to .info of index [3]
set .next of [6] to 3
set .next of index [2] to NUL
Here is the final list
| node | .info | .next |
| [0] | John | 4 |
| [1] | Mark | 5 |
| [2] | NUL | |
| [3] | Anne | NUL |
| [4] | Nell | 8 |
| [5] | Naomi | 6 |
| [6] | Robert | 3 |
| [7] | 2 | |
| [8] | Susan | 9 |
| [9] | Sussane | NUL |