#include

enum{FALSE=0,TRUE=-1};

/////////////////////////////////

///// Implements Priority Queue

/////////////////////////////////

class PriorityQueue // Class Prioriry Queue

{

private:

struct Node // Node of Priority Queue

{

struct Node *Previous;

int Data;

struct Node *Next;

}Current;

struct Node *head; // Pointer to Head

struct Node *ptr;

// Pointer for travelling through Queue

static int NumOfNodes;

// Keeps track of Number of nodes

public:

PriorityQueue(void);

int Maximum(void);

int Minimum(void);

void Insert(int);

int Delete(int);

void Display(void);

int Search (int);

~PriorityQueue(void);

};

// First Nodes Created With Constructor

int PriorityQueue::NumOfNodes=1;

// Constructor

PriorityQueue::PriorityQueue(void)

{

Current.Previous=NULL;

cout<<"Enter First Element of Queue"<

cin>>Current.Data;

Current.Next=NULL;

head=&Current;

ptr=head;

}

// Function Finding Maximum Priority Element

int PriorityQueue::Maximum(void)

{

int Temp;

ptr=head;

Temp=ptr->Data;

while(ptr->Next!=NULL)

{

if(ptr->Data>Temp)

Temp=ptr->Data;

ptr=ptr->Next;

}

if(ptr->Next==NULL && ptr->Data>Temp)

Temp=ptr->Data;

return(Temp);

}

// Function Finding Minimum Priority Element

int PriorityQueue::Minimum(void)

{

int Temp;

ptr=head;

Temp=ptr->Data;

while(ptr->Next!=NULL)

{

if(ptr->Data

Temp=ptr->Data;

ptr=ptr->Next;

}

if(ptr->Next==NULL && ptr->Data

Temp=ptr->Data;

return(Temp);

}

// Function inserting element in Priority Queue

void PriorityQueue::Insert(int DT)

{

struct Node *newnode;

newnode=new Node;

newnode->Data=DT;

while(ptr->Next!=NULL)

ptr=ptr->Next;

if(ptr->Next==NULL)

{

newnode->Next=ptr->Next;

ptr->Next=newnode;

}

NumOfNodes++;

}

// Function deleting element in Priority Queue

int PriorityQueue::Delete(int DataDel)

{

struct Node *mynode,*temp;

ptr=head;

if(NumOfNodes==1)

{

cout<<"Cannot Delete the only Node"<

return FALSE;

}

if(ptr->Data==DataDel)

{

/*** Checking condition for deletion of first node ***/

temp=ptr;

ptr=ptr->Next;

ptr->Previous=NULL;

//delete temp;

head=ptr;

NumOfNodes--;

return(TRUE);

}

else

{

while(ptr->Next->Next!=NULL)

{

/*** Checking condition for deletion of ***/

/*** all nodes except first and last node ***/

if(ptr->Next->Data==DataDel)

{

mynode=ptr;

temp=ptr->Next;

mynode->Next=mynode->Next->Next;

mynode->Next->Previous=ptr;

delete temp;

NumOfNodes--;

return(TRUE);

}

ptr=ptr->Next;

}

if(ptr->Next->Next==NULL && ptr->Next->Data==DataDel)

{

/*** Checking condition for deletion of last node ***/

temp=ptr->Next;

delete temp;

ptr->Next=NULL;

NumOfNodes--;

return(TRUE);

}

return(FALSE);

}

// Function Searching element in Priority Queue

int PriorityQueue::Search(int DataSearch)

{

ptr=head;

while(ptr->Next!=NULL)

{

if(ptr->Data==DataSearch)

return ptr->Data;

ptr=ptr->Next;

}

if(ptr->Next==NULL && ptr->Data==DataSearch)

return ptr->Data;

return(FALSE);

}

// Function Displaying elements of Priority Queue

void PriorityQueue::Display(void)

{

ptr=head;

cout<<"Priority Queue is as Follows:-"<

while(ptr!=NULL)

{

cout<Data<

ptr=ptr->Next;

}

// Destructor of Priority Queue

PriorityQueue::~PriorityQueue(void)

{

struct Node *temp; /* Temporary variable */

while(head->Next!=NULL)

{

temp=head->Next;

// delete head;

head=temp;

}

if(head->Next==NULL)

delete head;

}

//Main Function

void main()

{

PriorityQueue PQ;

int choice;

int DT;

while(1)

{

cout<<"Enter your choice"<

cout<<"1. Insert an element"<

cout<<"2. Display a priorty Queue"<

cout<<"3. Delete an element"<

cout<<"4. Search an element"<

cout<<"5. Exit"<

cin>>choice;

switch(choice)

{

case 1:

cout<<"Enter a Data to enter Queue"<

cin>>DT;

PQ.Insert(DT);

break;

case 2:

PQ.Display();

break;

case 3:

{

int choice;

cout<<"Enter your choice"<

cout<<"1. Maximum Priority Queue"<

cout<<"2. Minimum Priority Queue"<

cin>>choice;

switch(choice)

{

case 1:

PQ.Delete(PQ.Maximum());

break;

case 2:

PQ.Delete(PQ.Minimum());

break;

default:

cout<<"Sorry Not a correct choice"<

}

break;

case 4:

cout<<"Enter a Data to Search in Queue"<

cin>>DT;

if(PQ.Search(DT)!=FALSE)

cout<

else

cout<

break;

case 5:

exit(0);

default:

cout<<"Cannot process your choice"<

}

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