Presentation 3PM

#include <iostream>
//Source by - codewhoop.com / CodeWhoop - Youtube / Edited by Hilmi&Teng

using namespace std;

#define SIZE 5
int circleQueue[SIZE];
int front{ -1 };
int rear{ -1 };

bool ISempty();
void InsertQueue();
void Dequeue();
void ShowFrontRear();
void DisplayQueue();

int main()
{
    //1. We Will do a simple CLI choise.
    int choice{ 0 };
    bool isLooping{ true };
    do
    {
        cout << "\n-----------------------------------------------------\n";
        cout << " 1.Insert Queue\n 2.Dequeue\n 3.ShowFrontRear\n 4.Print All\n 5.End \n ";
        cout << "Choice :";
        cin >> choice;

        if (choice == 1) InsertQueue();
        if (choice == 3) ShowFrontRear();
        if (choice == 2) Dequeue();
        if (choice == 4) DisplayQueue();
        if (choice == 5) isLooping = false;

    } while (true);

}

bool ISempty()
{
    if (front == -1 && rear == -1)
    {
        return true;
    }
    return false;
}

void InsertQueue()
{
    int value{ 0 };
    cout << "Please enter value to be enQueued : ";
    cin >> value;

    //Find if Queue is full
    //1. If the rear index + 1 is equal to front means it's full
    if ((rear + 1) % SIZE == front)
    {
        cout << "Queue is full \n";
        return;
    }

    //if the first element is -1 make it 0;
    if (front == -1)
        front = 0;
    //Move the rear index forward and insert value
    rear = (rear + 1) % SIZE;
    circleQueue[rear] = value;
}

void Dequeue()
{
    // Check if the queue is empty so it will not underflow
    if (ISempty())
    {
        cout << "Queue is empty";
        return;
    }

    //If it's only one value left
    if (front == rear)
    {
        front = -1;
        rear = -1;
        return;
    }

    front = (front + 1) % SIZE;
}

void ShowFrontRear()
{
    if (ISempty())
    {
        cout << "Queue is empty";
        return;
    }

    cout << "\nElement at front is [" << front << "] " << endl;
    cout << "Element at rear is [" << rear << "] " << endl;
}

void DisplayQueue()
{
    if (ISempty())
    {
        cout << "Queue is empty";
        return;
    }
    int i;
    if (front <= rear)
    {
        for (i = front; i <= rear; i++)
            cout << circleQueue[i] << " ";
    }
    else
    {
        i = front;
        while (i < SIZE)
        {
            cout << circleQueue[i] << " ";
            i++;
        }
        i = 0;
        while (i <= rear)
        {
            cout << circleQueue[i] << " ";
            i++;
        }
    }

}