Function enqueue inserts the value in num
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The document outlines the implementation of an integer queue class in C++, demonstrating its construction, destruction, and core functionalities like enqueue, dequeue, isempty, isfull, and clear. It includes a main program that tests the queue by enqueuing five items, handling an attempt to enqueue an additional item when the queue is full, and dequeuing all items to display their values. The program outputs relevant messages indicating the state of the queue throughout these operations.
![IntQueue::IntQueue(int s) //constructor
{
queueArray = new int[s];
queueSize = s;
front = -1;
rear = -1;
numItems = 0;
}
IntQueue::~IntQueue(void) //destructor
{
delete [] queueArray;
}](https://image.slidesharecdn.com/lec-1213quees-copy3-copy-250119121724-ab4d0aed/85/Function-enqueue-inserts-the-value-in-num-1-320.jpg)
![//********************************************
// Function enqueue inserts the value in num *
// at the rear of the queue. *
//********************************************
void IntQueue::enqueue(int num)
{
if (isFull())
cout << "The queue is full.n";
else
{
// Calculate the new rear position
rear = (rear + 1) % queueSize;
// Insert new item
queueArray[rear] = num;
// Update item count
numItems++;
}
}](https://image.slidesharecdn.com/lec-1213quees-copy3-copy-250119121724-ab4d0aed/85/Function-enqueue-inserts-the-value-in-num-2-320.jpg)
![//*********************************************
// Function dequeue removes the value at the *
// front of the queue, and copies t into num. *
//*********************************************
int IntQueue::dequeue(void)
{
if (isEmpty())
cout << "The queue is empty.n";
else
{
// Retrieve the front item
int num = queueArray[front];
// Move front
front = (front + 1) % queueSize;
// Update item count
numItems--;
}
return num;
}](https://image.slidesharecdn.com/lec-1213quees-copy3-copy-250119121724-ab4d0aed/85/Function-enqueue-inserts-the-value-in-num-3-320.jpg)
Function enqueue inserts the value in num
- 1. IntQueue::IntQueue(int s) //constructor { queueArray = new int[s]; queueSize = s; front = -1; rear = -1; numItems = 0; } IntQueue::~IntQueue(void) //destructor { delete [] queueArray; }
- 2. //******************************************** // Function enqueue inserts the value in num * // at the rear of the queue. * //******************************************** void IntQueue::enqueue(int num) { if (isFull()) cout << "The queue is full.n"; else { // Calculate the new rear position rear = (rear + 1) % queueSize; // Insert new item queueArray[rear] = num; // Update item count numItems++; } }
- 3. //********************************************* // Function dequeue removes the value at the * // front of the queue, and copies t into num. * //********************************************* int IntQueue::dequeue(void) { if (isEmpty()) cout << "The queue is empty.n"; else { // Retrieve the front item int num = queueArray[front]; // Move front front = (front + 1) % queueSize; // Update item count numItems--; } return num; }
- 4. //********************************************* // Function isEmpty returns true if the queue * // is empty, and false otherwise. * //********************************************* bool IntQueue::isEmpty(void) { if (numItems) return false; else return true; }
- 5. //******************************************** // Function isFull returns true if the queue * // is full, and false otherwise. * //******************************************** bool IntQueue::isFull(void) { if (numItems < queueSize) return false; else return true; }
- 6. //******************************************* // Function clear resets the front and rear * // indices, and sets numItems to 0. * //******************************************* void IntQueue::clear(void) { front = - 1; rear = - 1; numItems = 0; }
- 7. //Program demonstrating the IntQueue class void main(void) { IntQueue iQueue(5); cout << "Enqueuing 5 items...n"; // Enqueue 5 items. for (int x = 0; x < 5; x++) iQueue.enqueue(x); // Attempt to enqueue a 6th item. cout << "Now attempting to enqueue again...n"; iQueue.enqueue(5); // Deqeue and retrieve all items in the queue cout << "The values in the queue were:n"; while (!iQueue.isEmpty()) { int value; iQueue.dequeue(value); cout << value << endl; } }
- 8. Program Output Enqueuing 5 items... Now attempting to enqueue again... The queue is full. The values in the queue were: 0 1 2 3 4