Double-Ended Queue in Data Structure

#include<iostream.h>

#include<conio.h>

classsqueue

{

private:

squeue *prev,*next;

int data;

public :

voidaddrear(int);

void display(void);

voidremovefront(void);

voidaddfront(int);

voidremoverear(void);

};

squeue *front;

squeue *rear;

voidsqueue::addrear(intnum)

{

squeue *temp;

if(front==NULL && rear==NULL)

 {

front=rear=new squeue;

front->prev=NULL;

front->next=NULL;

front->data=num;

 }

else

 {

rear->next=new squeue;

rear->next->data=num;

rear->next->prev=rear;

rear->next->next=NULL;

rear=rear->next;

 }}

voidsqueue::addfront(intnum)

{

squeue *temp=front;

if(front==NULL && rear==NULL)

 {

front=rear=new squeue;

front->prev=NULL;

front->next=NULL;

front->data=num;

 }

else

 {

front=new squeue();

front->data=num;

front->prev=NULL;

front->next=temp;

temp->prev=front;

 }}

voidsqueue::display()

{

squeue *q=front;

if(front==NULL && rear==NULL)

{

cout<<"no queue";

}

else

{

while(q!=NULL)

{

cout<<q->data<<"\t";

q=q->next;

}}}

voidsqueue::removefront()

{

squeue *temp=front;

front=front->next;

front->prev=NULL;

cout<<endl<<temp->data<<" is removed\n";

delete(temp);

display();

}

voidsqueue::removerear()

{

squeue *temp=rear;

rear=rear->prev;

rear->next=NULL;

cout<<endl<<temp->data<<" is removed\n";

delete(temp);

display();

}

void main(){

clrscr();

squeue s;

char c='y';

intopt,num;

while(c=='y')

{

cout<<"\n 1.add R \n 2. display  \n 3. remove F \n 4. add F \n 5. Remove R \n enter option: ";

cin>>opt;

switch(opt)

{

case 1:

cout<<"enter number in queue:";

cin>>num;

s.addrear(num);

cout<<"\ndo you want to continue:";

break;

case 2:

s.display();

cout<<"\ndo you want to continue:";

break;

case 3:

s.removefront();

cout<<"\ndo you want to continue:";

break;

case 4:

cout<<"enter number in queue:";

cin>>num;

s.addfront(num);

cout<<"\ndo you want to continue:";

break;

case 5:

s.removerear();

cout<<"\ndo you want to continue:";

break;

default:

cout<<"wrng selection";

cout<<"\ndo you want to continue:";

break;}

c=getch();

}

getch();

}

Circular Queue program in Data Structure

#include<iostream.h>

#include<conio.h>

classsqueue

{

private:

squeue *prev,*next;

int data;

public :

void add(int);

void display(void);

void remove(void);

};

squeue *front;

squeue *rear;

voidsqueue::add(intnum)

{

squeue *temp;

if(front==NULL && rear==NULL)

 {

front=rear=new squeue;

front->prev=NULL;

front->next=NULL;

front->data=num;

 }

else

 {

temp=front;

rear->next=new squeue;

rear->next->data=num;

rear->next->prev=rear;

rear->next->next=front;

rear=rear->next;

front->prev=rear;

 }}

voidsqueue::display()

{

squeue *q=front;

if(front==NULL && rear==NULL)

{

cout<<"no queue";

}

else

{do

{

cout<<q->data<<"\t";

q=q->next;

}

while(q!=rear->next);

}}

voidsqueue::remove()

{

squeue *temp=front;

front=front->next;

front->prev=NULL;

cout<<endl<<temp->data<<" is removed\n";

delete(temp);

display();

}

void main()

{

clrscr();

squeue s;

char c='y';

intopt,num;

while(c=='y')

{

cout<<"\n 1.add \n 2. display  \nenter option: ";

cin>>opt;

switch(opt)

{

case 1:

cout<<"enter number in queue:";

cin>>num;

s.add(num);

cout<<"\ndo you want to continue:";

break;

case 2:

s.display();

cout<<"\ndo you want to continue:";

break;

case 3:

s.remove();

cout<<"\ndo you want to continue:";

break;

default:

cout<<"wrng selection";

cout<<"\ndo you want to continue:";

break;

}c=getch();

}getch();}

Simple Queue program in Data Structure

#include<iostream.h>

#include<conio.h>

class queue

{

private:

int data;

queue *prev;

queue *next;

public:

void add(int);

void display(void);

void remove(void);

};

queue *front;

queue *rear;

void queue::add(intnum)

{

if((front==NULL)&&(rear==NULL))

{

front=rear=new queue;

front->data=num;

front->next=NULL;

front->prev=NULL;

}

else

{

rear->next=new queue;

rear->next->data=num;

rear->next->next=NULL;

rear->next->prev=rear;

rear=rear->next;

}}

void queue::display(void)

{

queue *q=front;

if((front==NULL)&&(rear==NULL))

  {

cout<<"Queue is empty";

  }

else

  {

while(q!=NULL)

    {

cout<<q->data<<endl;

      q=q->next;

    }}}

void queue::remove(void)

{

queue *q=front;

if((front==NULL)&&(rear==NULL))

   {

cout<<"Queue is empty"<<endl;

   }

else

   {

front=front->next;

front->prev=NULL;

cout<<q->data<<"/t"<<"is deleted"<<endl;

delete(q);

   }}

void main()

  {

clrscr();

queue q1;

intnum;

int option;

char choice='y';

while(choice=='y')

   {

cout<<"1.ADD"<<endl;

cout<<"2.DISPLAY"<<endl;

cout<<"3.REMOVE"<<endl;

cout<<"Select the option";

cin>>option;

switch(option)

     {

case 1:

       {

cout<<"enter the data";

cin>>num;

q1.add(num);

cout<<"Continue?"<<endl;

break;

       }

case 2:

       {

                q1.display();

                cout<<endl;

                cout<<"Continue?"<<endl;

                break;  }

case 3:

       {

                q1.remove();

                cout<<endl;

                cout<<"Continue?";

                break;}

default:

                {

                cout<<"wrong option";

                cout<<"Continue";

                break;

                 }}

                choice=getch();

     }   }

Stack program in Data Structure

#include<iostream.h>

#include<conio.h>

class stack

{

int data;

stack *next,*prev;

public:

void push(int);

int pop();

void display();

};

stack *bottom,*top;

/* push function*/

void stack::push(int num)

{

if((bottom==NULL)&&(top==NULL))

{

top=bottom=new stack;

top->data=num;

top->next=NULL;

top->prev=NULL;

}

else

{

top->next=new stack;

top->next->data=num;

top->next->prev=top;

top->next->next=NULL;

top=top->next;

}

}

/* display  function*/

 void stack:: display()

{       

 stack *q=bottom;

 if(bottom==NULL)

 {

 cout<<"\n\nStack is empty";

 }

 else {

 while(q!=NULL)

{

cout<<"\t "<<q->data;

q=q->next;

}

}

}

/*pop  function*/

int stack::pop()

{     int result;

if((bottom==NULL)&&(top==NULL))

{

return -1;

}

result=top->data;

top=top->prev;

if(top!=NULL)

{

delete(top->next);

top->next=NULL;

return result;

}

else

{

delete(bottom);

bottom=NULL;

return result;

}

}

/*main()  function*/

void main()

{

stack n1;

int ch;

char c;

do

{    

clrscr();

cout<<"\n 1: PUSH  2: DISPLAY  3: POP";

cout<<"\n\n Enter Your Choice: ";

cin>>ch;

switch(ch)

{

case 1:

cout<<"\n\n Enter Any number: " ;

int num;

cin>>num;

n1.push(num);

break;

case 2:

n1.display();

break;

case 3:

int n=n1.pop();

if(n==-1)

{

cout<<"\n\n Stack is empty";

}

else

{

cout<<"\n\n Popped Item is: "<<n;

}

break;

default:

cout<<"\n wrong selection";

break;

}

cout<<"\n\n Do you want to continue(y/n): ";

cin>>c;

}

while(c=='y');

}