BY : SADIA ZAR

Two Basic Operations in Queue

Enque : Inserting new element from rear end

Deque : Removing existing element from front end

Front End

Rear End

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#include <iostream>

using namespace std;

class Queue

{

int* array,size,f,r,count;

public:

Queue();

void Enque(int value);

int Deque();

bool is_Empty();

bool is_Full();

};

Queue::Queue()

{

cout<<"Enter size : ";

cin>>size;

array=new int[size];

f=r=-1;

count=0;

}

void Queue::Enque(int value){

if(!is_Full()){

array[++r]=value;count++;

}else{

cout<<"\n\nOverFlow ! \n\n";}

}

int Queue::Deque()

{

if(!is_Empty())

{

count--;

return array[++f];

}

else

{

cout<<"\n\nUnderFlow ! \n\n";

}

}

bool Queue::is_Empty()

{

return f==r==-1;

}

bool Queue::is_Full()

{

return count==size;

}

void main(){Queue obj;obj.Enque(1);obj.Enque(2);obj.Enque(3);obj.Deque();

}

1 2 3

0 1 2 3 4 5 6

#include <iostream>using namespace std;class Node{

int value;Node*next;friend class Queue;public:Node(){

next=NULL;}

};

class Queue{

Node *first,*last;public:Queue(){

first=last=NULL;}void Enque(int v);bool is_Empty();void Deque();void Display();

};

first

last

void Queue::Enque(int v){

Node *n=new Node(); n->value=v;if(first==NULL){

last=first=n;}else{

last->next=n;last=n;

}}

DATA

NEXT

void Queue::Deque(){

if(!is_Empty()){

Node *temp=first;first=first->next;cout<<"\n\nThe data Dequeued is : "<<temp->value<<endl;delete temp;

}}

bool Queue::is_Empty()

{

return first==NULL||last==NULL;

}

void Queue::Display()

{

Node *p = new Node;

p = first;

cout<<"\n\nQueue Elements are : \n\n";

while(p!=NULL)

{

cout<<p->value<<endl;

p = p->next;

}

}

Void main(){

Queue Q;Q.Enque(12); Q.Enque(15);Q. Deque();Q .Display();

}

100

200

12

15

200

NULL

100

200

first

last

200