Program 18

         

ARRAY IMPLEMENTATION OF QUEUE

Write a program to perform insertion and deletion in an array Queue

/* Program to create a Linear Queue using an array to perform insertion, deletion and display operations*/

#include < iostream . h >

#include  < process . h >

#include < conio . h >

# define MAX 10

class Queue

 {

          int queue[ MAX ] ;

          int front, rear ;

     public :

          Queue ( )

           {

                   front = rear = -1 ;  //denotes Q is empty

           }

          void add_to_Q ( )

           {

                   if ( rear == MAX - 1 )

                     {

                             cout<<"Queue is Full  !! " ;

                     }

                   else

                     {

                             int n ;

                             cout << "\nEnter the no to be added:: " ;

                             cin  >> n ;

                             queue [ ++rear ] = n ;

                             if( front == -1 )

                               front = rear;

                             cout<<"\nAdded to the Queue !! " ;

                     }

           }

          void del_from_Q ( )

           {

                   if ( front == -1 )

                    {

                             cout<< " Queue is empty !! Cannot delete !! " ;

                    }

                   else

                    {

                             cout<< "Element deleted :: " << queue [ front ++ ] ;

                    }

           }

          void display_Q ( )

           {

                   if ( front == -1 )

                             cout << "Queue is empty !! ";

                   else

                    {

                             cout<< "\nQueue is ::\t";

                             for ( int i = front ; i <=rear ; ++ i)

                                      cout << queue [ i ] << "\t" ;

                    }

           }

 } Q ;

void main ( )

 {

          int ch ;

          clrscr( ) ;

          while ( 1 )

           {

                   cout << "\n1. Add to Queue ";

                   cout << "\n2. Delete from Queue" ;

                   cout << "\n3. Display Queue" ;

                   cout << "\n4. Exit" ;

                   cout << "\nEnter your choice :: " ;

                   cin  >> ch ;

                   if ( ch == 1 )

                             Q.add_to_Q ( ) ;

                   if ( ch == 2 )

                             Q.del_from_Q ( ) ;

                   if ( ch == 3 )

                             Q. display_Q ( ) ;

                   if ( ch == 4 )

                             exit ( 0 ) ;

                   getch ( ) ;

           }

 }