What is Queue In Data Structures? Implementation Using C++.

 

Queue in Data Structures:

The queue is an abstract data structure, somewhat similar to Stacks. Unlike stacks, a queue is open at both its ends. One end is always used to insert data (enqueue) and the other is used to remove data (dequeue). Queue follows First-In-First-Out methodology, i.e., the data item stored first will be accessed first.

For Example:

A real-world example of a queue can be a single-lane one-way road, where the vehicle enters first, exits first. More real-world examples can be seen as queues at the ticket windows and bus-stops.

Queue Implementation Using C++

#include<iostream>

using namespace::std;

 class ArrayBasedQueue{

  private:

    int array[5];

    int rear,front,noofelem;

    public:

     ArrayBasedQueue()

     {

      front=-1;

      rear=0;

      noofelem=0;

     }

  void enqueue(int value){

   if(noofelem==5)

   cout<<"Queue Is Full !"<<endl;

   else{

    array[rear]=value;

    cout<<"Value Is Enqueue At Index No. "<<rear;

    cout<<" Is :"<<array[rear++]<<endl;

    noofelem++;

   }

  }

 void dequeue(){

  if(noofelem==0)

  cout<<"Queue Is Empty !"<<endl;

       else{

         cout<<"The Value Dequeue From Index No. "<<front<< " Is :"<<array[++front]<<endl;

         noofelem--;

    }

 }

 };

 int main(){

  ArrayBasedQueue* queue =new ArrayBasedQueue();

  queue->enqueue(33);

  queue->enqueue(18);

  queue->enqueue(20);

  queue->enqueue(74);

  queue->enqueue(65);

  queue->enqueue(34);

  queue->enqueue(65);

  queue->enqueue(34);

  queue->dequeue();

  queue->dequeue();

  queue->dequeue();

  queue->dequeue();

  queue->dequeue();

  queue->dequeue();

  queue->dequeue();

  queue->dequeue();

  }