Question

Study and implement data structure deque (double ended queue, pronounced as "deck").

IN C++ PLEASE

Answer 1

#include<iostream>

using namespace std;

#define MAX 100

class Deque

{

  int arr[MAX];

  int front;

  int rear;

  int size;

public :

  Deque(int size)

  {

    front = -1;

    rear = 0;

    this->size = size;

  }

  void insertfront(int key);

  void insertrear(int key);

  void deletefront();

  void deleterear();

  bool isFull();

  bool isEmpty();

  int getFront();

  int getRear();

};

bool Deque::isFull()

{

  return ((front == 0 && rear == size-1)||

      front == rear+1);

}

bool Deque::isEmpty ()

{

  return (front == -1);

}

void Deque::insertfront(int key)

{

  if (isFull())

  {

    cout << "Overflow\n" << endl;

    return;

  }

  if (front == -1)

  {

    front = 0;

    rear = 0;

  }

  else if (front == 0)

    front = size - 1 ;

  else

    front = front-1;

  arr[front] = key ;

}

void Deque ::insertrear(int key)

{

  if (isFull())

  {

    cout << " Overflow\n " << endl;

    return;

  }

  if (front == -1)

  {

    front = 0;

    rear = 0;

  }

  else if (rear == size-1)

    rear = 0;

  else

    rear = rear+1;

  arr[rear] = key ;

}

void Deque ::deletefront()

{

  if (isEmpty())

  {

    cout << "Queue Underflow\n" << endl;

    return ;

  }

  if (front == rear)

  {

    front = -1;

    rear = -1;

  }

  else

    if (front == size -1)

      front = 0;

    else

      front = front+1;

}

void Deque::deleterear()

{

  if (isEmpty())

  {

    cout << " Underflow\n" << endl ;

    return ;

  }

  if (front == rear)

  {

    front = -1;

    rear = -1;

  }

  else if (rear == 0)

    rear = size-1;

  else

    rear = rear-1;

}

int Deque::getFront()

{

  if (isEmpty())

  {

    cout << " Underflow\n" << endl;

    return -1 ;

  }

  return arr[front];

}

int Deque::getRear()

{

  if(isEmpty() || rear < 0)

  {

    cout << " Underflow\n" << endl;

    return -1 ;

  }

  return arr[rear];

}