Chapter 21, Problem 5FTE

Explanation of Solution

Program purpose:

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

Logical error:

Logical error is a mistake in a program’s source code that leads to produce an incorrect output. This error is a type of run time error, as it cannot be identified during the compilation of the program. This is a logical mistakes created by the programmer and it is determined when the program produces wrong output.

Error #1:

The “dequeue()” function should remove from the front end, not from the rear end.

Correct statement:

//assigning value of at the front to a variable val.

int val=q[front];

/*removing value at front by incrementing the value of front by one*/

front++;

Error #2:

The statement used to wrap the indices “front” and “rear” to “0” is missing. It should be done for saving the memory when the “dequeue()” method is popped all the elements.

Correct statement:

/*checking whether value of front is equal to length of the queue*/

if(front == q.length)

//set front to 0

front=0;

Corrected code:

//An array implementation of a queue

int dequeue()

{

    //checking whether the queue is empty

    if (empty())

/*throws an exception EmptyQueueException indicating that there is no elements available    to remove...