int front = 0;
int rear = -1;
int count = 0;
front → points to the first element.
rear → points to the last element.
count → stores the number of elements in the queue.
For example:
Queue: 10 20 30
↑ ↑
front rear
count = 3
When 10 is deleted:
Queue: 20 30
↑ ↑
front rear
count = 2
Enqueue = Insert
Dequeue = Delete
Count = Number of elements
#include <iostream>
using namespace std;
int queue[5];
int front = 0;
int rear = -1;
int count = 0;
// Insert element into Queue
void enqueue(int value)
{
if (count == 5)
{
cout << "Queue is Full" << endl;
}
else
{
rear++;
queue[rear] = value;
Count++;
cout << value << " inserted" << endl;
}
}
// Delete element from Queue
void dequeue()
{
if (count == 0)
{
cout << "Queue is Empty" << endl;
}
else
{
cout << queue[front] << " deleted" << endl;
front++;
count--;
}
}
// Peek/Front - View the first element
void peek()
{
if (count == 0)
{
cout << "Queue is Empty" << endl;
}
else
{
cout << "Front element: " << queue[front] << endl;
}
}
// Display Queue
void display()
{
if (count == 0)
{
cout << "Queue is Empty" << endl;
}
else
{
cout << "Queue elements: ";
for (int i = front; i <= rear; i++)
{
cout << queue[i] << " ";
}
cout << endl;
}
}
// Display number of elements
void displayCount()
{
cout << "Number of elements: " << count << endl;
}
int main()
{
enqueue(10);
enqueue(20);
enqueue(30);
display();
displayCount();
dequeue();
peek();
display();
displayCount();
return 0;
}
