C++ Programming Code Examples

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C++ Program to Implement Queue using Linked List

C++ Program to Implement Queue using Linked List

This C++ program, using iteration, implements the list of elements removed from the queue in first in first out mode using a linked list. A linked list is an ordered set of data elements, each containing a link to its successor.

    #include<iostream>

    #include<stdio.h>

    #include<conio.h>

    using namespace std;

    struct node

    {

        int data;

        node *next;

    }*front = NULL,*rear = NULL,*p = NULL,*np = NULL;

    void push(int x)

    {

        np = new node;

        np->data = x;

        np->next = NULL;

        if(front == NULL)

        {

            front = rear = np;

            rear->next = NULL;

        }

        else

        {

            rear->next = np;

            rear = np;

            rear->next = NULL;

        }

    }

    int remove()

    {

        int x;

        if(front == NULL)

        {

            cout<<"empty queue\n";

        }

        else

        {

            p = front;

            x = p->data;

            front = front->next;

            delete(p);

            return(x);

        }

    }

    int main()

    {

        int n,c = 0,x;

        cout<<"Enter the number of values to be pushed into queue\n";

        cin>>n;

        while (c < n)

        {

    	cout<<"Enter the value to be entered into queue\n";

    	cin>>x;

            push(x);

            c++;

         }

         cout<<"\n\nRemoved Values\n\n";

         while(true)

         {

            if (front != NULL)

                cout<<remove()<<endl;

            else

                break;

         }

         getch();

    }