Chapter 20, Problem 4FTE

Explanation of Solution

Program purpose:

The given program is used to implement queue using linked list.

Syntax error:

An error that occurs on the source code of a program is referred as a “syntax error”, because the computer programs strictly follow the syntax rules. If the code fails to prove its language syntax format, then the compiler will throw an error.

Error in the code:

The operator “++” cannot be applied to a reference.  Use front = front.next;

Correct statement:

/*removing the element from front by moving front to the next node.*/

front= front.next;

Corrected code:

//A linked implementation of a queue

int dequeue()

{

    //checks whether the queue is empty

    if(empty())

/*throws exception EmptyQueueException indicating the queue is empty*/

        throw new EmptyQueueException();

    /*if the queue is not empty then,

    front element is reserved to a variable*/

    int value= front...