Queue

 

#include<iostream>

using namespace std;

class queue

{private: struct node

{int element;

node*next;

}*head;

public:

queue();

void inqueue(int element);

int  dqueue();

void inject(int element);

int  eject();

void diepaly();

bool isempty();

void display();

~queue();};

queue::queue()

{

  head=NULL;}

bool queue::isempty()

{if(head==NULL)

return true;

else

return false;}

void queue::inqueue(int element)

{if(isempty())

{

head=new node;

head->element=element;

head->next=NULL;

return;}

 

node*curr=head;

while(curr->next!=NULL)

curr=curr->next;

node* t=new node;

t->element=element;

t->next=NULL;

curr->next=t;

cout<<"ram";

}

int queue::dqueue()

{

if(isempty())

{cout<<"\nqueue is empty";

return -10000;}

node*t=head;

head=head->next;

int data=t->element;

delete(t);

return data;

}

void queue::inject(int element)

{if(isempty())

{

head=new node;

head->element=element;

head->next=NULL;

return;}

node*t=new node;

t->element=element;

t->next=head;

head=t;

}

int queue::eject()

{if(isempty())

{cout<<"\n queue is empty";

return -10000;}

node*curr;

curr=head;

if(head->next==NULL){

int data=head->element;

head=NULL;

}

while(curr->next->next!=NULL)

curr=curr->next;

node*t=curr->next;

int data=t->element;

curr->next=NULL;

delete(t);

return data;

 

}

void  queue::display()

{if(isempty()){

cout<<"\n queue is empty";

return;

}

 

node*curr=head;

cout<<endl;

while(curr!=NULL){

cout<<curr->element<<"->->";

curr=curr->next;}}

queue::~queue(){

while(head!=NULL){

node*t=head;

head=head->next;

delete(t);}}

int main()

{ int a;

char c;

queue q;

cout<<"\t\t********WELCOME TO QUEUE OPERATION************\n";

cout<<"\t----------------------------------------------------------------------\n";

do

{cout<<"\n\t\t\tpress 1 for  inqueue\n\t\t\tpress 2 for dqueue\n\t\t\tpress 3 for enject in queue\n\t\t\tpress 4 for  eject from queue\n\t\t\t 5 to display queue element\n";

cout<<"\n enter your choice\t";

cin>>a;

switch(a)

{case 1:cout<<"\n enter the element you want to inqueue\t";

int b;

cin>>b;

q.inqueue(b);

break;

case 2:int d;

d=q.dqueue();

if(d!=-10000)

cout<<"the element dqueued is\t"<<d;

break;

case 3:

cout<<"\n enter the element you want to injuct in queue\t";

int e;

cin>>e;

q.inject(e);

break;

case 4:

int f;

f=q.eject();

if(f!=-10000)

cout<<"\n the element ejected is\t"<<f;

break;

case 5:

cout<<"\n-------------------------------------------------------------------------------";

q.display();

cout<<"\n---------------------------------------------------------------------------";

break;

defoult:

cout<<"\n sorry you entered wrong option";}

cout<<"\n do yow you want to continue  if yes press y";

cin>>c;}while(c=='y');

 

 

}