Answer to Question #296476 in C++ for Roe

Question

Make an array based circular queue

Make a function as follows

bool search(int key)

This function searches if element exists in circular queue or not

Requirements :

Test run in main

No global decelerations

Answer 1

#include <iostream>


using namespace std;


class Queue
{
    int rear, front;


    int size;
    int* arr;


public:
    Queue(int s)
    {
        front = rear = -1;
        size = s;
        arr = new int[s];
    }


    void enQueue(int value);
    int deQueue();
    void displayQueue();
    bool search(int key);
};






bool Queue::search(int key)
{
    for (int i = 0; i < size; i++)
    {
        if (arr[i] == key)
        {
            return 1;
        }
    }
    return 0;
}
void Queue::enQueue(int value)
{
    if ((front == 0 && rear == size - 1) ||
        (rear == (front - 1) % (size - 1)))
    {
        printf("\nQueue is Full");
        return;
    }


    else if (front == -1) 
    {
        front = rear = 0;
        arr[rear] = value;
    }


    else if (rear == size - 1 && front != 0)
    {
        rear = 0;
        arr[rear] = value;
    }


    else
    {
        rear++;
        arr[rear] = value;
    }
}




int Queue::deQueue()
{
    if (front == -1)
    {
        printf("\nQueue is Empty");
        return INT_MIN;
    }


    int data = arr[front];
    arr[front] = -1;
    if (front == rear)
    {
        front = -1;
        rear = -1;
    }
    else if (front == size - 1)
        front = 0;
    else
        front++;


    return data;
}




void Queue::displayQueue()
{
    if (front == -1)
    {
        printf("\nQueue is Empty");
        return;
    }
    printf("\nElements in Circular Queue are: ");
    if (rear >= front)
    {
        for (int i = front; i <= rear; i++)
            printf("%d ", arr[i]);
    }
    else
    {
        for (int i = front; i < size; i++)
            printf("%d ", arr[i]);


        for (int i = 0; i <= rear; i++)
            printf("%d ", arr[i]);
    }
}




int main()
{
    Queue q(5);




    q.enQueue(14);
    q.enQueue(22);
    q.enQueue(13);
    q.enQueue(-6);




    q.displayQueue();
    int value = 0;
    std::cout << "\nEnter value to search : ";
    std::cin >> value;




    if (q.search(value))
    {
        std::cout << "There is such value\n";
    }
    else
    {
        std::cout << "There is no such value\n";
    }
    system("pause");
    return 0;
}