Practical_32(C++).cpp

/*
Pizza parlor accepting maximum M orders. 
Orders are served in first come first served basis. Order once placed can not be cancelled. 
Write C++ program to simulate the system using circular queue using array.
*/

#include<iostream>
#include<cstdlib>
using namespace std;

class pizza {
    int front, rear, q[5];
public:
    pizza() {
        front = -1;
        rear = -1;
    }
    int isfull() {
        if ((front == 0 && rear == 4) || front == (rear + 1) % 5) {
            return 1;
        } else {
            return 0;
        }
    }
    int isempty() {
        if (front == -1 && rear == -1) {
            return 1;
        } else {
            return 0;
        }
    }
    void add() {
        if (isfull() == 0) {
            cout << "\n Enter the Pizza ID: ";
            if (front == -1 && rear == -1) {
                front = 0;
                rear = 0;
                cin >> q[rear];
            } else {
                rear = (rear + 1) % 5;
                cin >> q[rear];
            }
            char c;
            cout << " Do you want to add another order? ";
            cin >> c;
            if (c == 'y' || c == 'Y')
                add();
        } else {
            cout << "\n Orders are full ";
        }
    }
    void serve() {
        if (isempty() == 0) {
            if (front == rear) {
                cout << "\n Order served is : " << q[front];
                front = -1;
                rear = -1;
            } else {
                cout << "\n Order served is : " << q[front];
                front = (front + 1) % 5;
            }
        } else {
            cout << "\n Orders are empty ";
        }
    }
    void display() {
        if (isempty() == 0) {
            for (int i = front; i != rear; i = (i + 1) % 5) {
                cout << q[i] << " <- ";
            }
            cout << q[rear];
        } else {
            cout << "\n Orders are empty";
        }
    }
    void check() {
        int ch;
        cout << "\n\n * * * * PIZZA PARLOUR * * * * \n\n";
        cout << "\n 1. Add a Pizza \n 2. Display the Orders \n 3. Serve a pizza \n 4. Exit \n Enter your choice : ";
        cin >> ch;
        switch (ch) {
            case 1:
                add();
                break;

            case 2:
                display();
                break;

            case 3:
                serve();
                break;

            case 4:
                exit(0);

            default:
                cout << "Invalid choice ";

                check();
        }
        char ch1;
        cout << "\n Do you want to continue? ";
        cin >> ch1;
        if (ch1 == 'y' || ch1 == 'Y')
            check();
    }
};

int main() {
    pizza p1;
    p1.check();
    return 0;
}