Chapter 3, Problem 27C

Explanation of Solution

Algorithm to swap two nodes in singly linked list:

The algorithm to swap two nodes “x” and “y” in singly linked list “L” is given below:

Algorithm:

Input: Two nodes “x” and “y”.

Output: Swap the two nodes in singly linked list “L”.

swapSingly(x, y):

  //Create a node to assign the head into it

  Node n = head;

/*Loop executes until the next node of head is not equal to "x" node. */

  while(n.getNext() != x)

/*Get next node of head and assign it into "n" node. */

  n = n.getNext();

/*Get the next node of "y" node and assign it into "v" node. */

  Node v = y.getNext();

/*Call setNext() method to set the next node as "y" node by using "n".*/

  n.setNext(y);

/*Call setNext() method to set the next node as "x" node by using "y". */

  y.setNext(x);

/*Call setNext() method to set the next node as "v" node by using "x". */

  x.setNext(v);

Explanation:

In the above algorithm,

• This method accepts two input parameters such as “x” and “y”.
• Create new node “n” and “v” to hold nodes “x” and “y” from singly linked lists.
• The while loop executes until the next node of head is not equal to “x” node.
  • Get next node of head and assign it into “n” node.
• Get the next node of “y” node and assign it into “v” node.
• Call setNext() method to set the next node as “y” node by using “n”.
• Call setNext() method to set the next node as “x” node by using “y”.
• Call setNext() method to set the next node as “v” node by using “x”.
• Finally, the two nodes “x” and “y” are swapped in singly linked list.

Algorithm to swap two nodes in doubly linked list:

The algorithm to swap two nodes “x” and “y” in singly linked list “L” is given below:

Algorithm:

Input: Two nodes “x” and “y”.

Output: Swap the two nodes in doubly linked list “L”.

swapDoubly(x, y):

/*Create a node to assign the previous node of "x" node into it...