Question

Data Structures and Algorithms (Java Programming)

a) When devising an algorithm for linked lists, why must you be careful about the order in which you change the references?

b) What code would be needed to change the references in a linked list when moving up one node?

c) Why did we have a previous reference in our linked list implementation?

d) Write a class for a linked list node with just one constructor that allows the initialization of all instance variables.

Answer 1

1.While devising an algorithm for linked lists, we be careful about the order in which you change the references.Because those references are used to traverse the linked lit.if the references were not perfectly assigned the linked list wont work properly..

hence we have to be careful about reference assigning in linked list.

2.The moving up should be done in linked list the current element has a next element i.e next!=NULL

hence the code is...

node *start=head of the tail;

while(start!=NULL)

{

//now start is a node.......can do your operations..

System.out.println("NODE ::"+start.data);

//moving up one node

start=start.next;

}

3.The previous reference in the linked ist node i used when we are removing a node from the inked list....

when removing a node,we have to change the previous node of the current node point so that its next reference points to the next reference of the current node.....

i.e. NULL<--A-><-B-><-C->NULL

while deleting B....

NULL<--A-><-C->NULL

hence the previous reference is needed to delete a node successfully....

4.

1.class Node
2.{
3. public int data;
4. public Node next, prev;
5. public Node(int d, Node n, Node p)
6. {
7. data = d;
8. next = n;
9. prev = p;

10.   }

11 .}