Data Structures Using C, 2nd Edition by Pearson

Linked Lists 263

The effect of the above program segment is shown in Figure 6.27. The above three operations have

been labeled as 1–3 in Figure 6.27.

Fig. 6.26 Insertion of node X after a node pointed by ptr

NULL

NULL

First

X

ptr

1

2 3

4

Note: During insertion or deletion of a node, the leftLink and rightLink pointers are appropriately

fixed so that they point to the correct node in the list.

From Figures 6.23 to 6.27, it may be observed that the doubly linked list has the following advan-

tages over the singly linked list:

(1) With the help of rightLink, the list can be traversed in forward direction.

(2) With the help of leftLink, the list can be traver ...