C and C++ Examples (Queue using Arrays)

       /* PROGRAM TO IMPLEMENT QUEUE USING ARRAYS */
#include<iostream.h>
#include<process.h>
#include<conio.h>
class queue
{
 int *a,front,rear,n;
public:
queue()
 {
 clrscr();
 front=rear=-1;
 cout<<"\n enter the size of the queue:";
 cin>>n;
 a=new int[n];
 }
 void insertion();
 void deletion();
 void print();
};
void queue::insertion()
{
int num;
if(rear==n-1)
 {
 cout<<"\n queue overflow \n";
 return;
 }
 cout<<"\n enter a number:";
 cin>>num;
 if(front==-1)
 front=rear=0;
 else
 rear++;
 a[rear]=num;
 cout<<num<<"number is inserted into queue \n";
}
void queue::deletion()
{
if(front==-1)
{
 cout<<"\n queue underflow \n";
 return;
}
cout<<"\n deleted element is "<<a[front]<<"\n";
if(front==rear)
 front=rear=-1;
else
 front++;
 cout<<"\n number is deleted \n";
}
void queue::print()
{
if(front==-1)
 cout<<"QUEUE IS EMPTY:";
for(int i=front;i<=rear;i++)
 cout<<"\n"<<a[i]<<"\n";
}
void main()
{
queue q;
int op;
clrscr();
while(1)
 {
cout<<"\n QUEUE ELEMENTS ARE::\n";
q.print();
cout<<"\n 1.insertion\n2.deletion\n3.exit\n";
cout<<"\n enter your option \n";
cin>>op;
switch(op)
{
case 1:q.insertion();
break;
case 2:q.deletion();
break;
case 3:exit(0);
}
getch();
 }
}



ouput :


QUEUE ELEMENTS ARE::
QUEUE IS EMPTY:
0

1.insertion
2.deletion
3.exit

enter your option
1

enter a number:15
15
number is inserted into queue

QUEUE ELEMENTS ARE::

15

1.insertion
2.deletion
3.exit

enter your option
2

deleted element is 15

number is deleted

Posted in: Programming