Java Applets Centre

Queue

Description
This applet demonstrates the basic operations on a queue data structure. The "Insert" operation adds an element to the "rear" end of the queue, and takes O(1) time. Deletions take place at the "front" end of the queue, and take O(n) time.

Insert: Inserts an element into the queue. This applet inserts a randomly generated value, when the "Insert" button is clicked.

Delete: Deletes an elament from the front of the queue, and re-positions the remaining elements.

Front: Reads the value at the front of the queue.

Code (An array-based queue)

public void insert(int val){
q[++tail]=val;
}
public void delete(){
if(!isEmpty()){
   for(int i=0; i< tail; i++)
    q[i]=q[i+1];
    tail--;
   }
}
}
public int front(){
return q[0];
}
public boolean isEmpty(){
return (tail==-1)? true:false;
}

Data Structures and Algorithms
Java Applets Centre

R. Mukundan
Department of Computer Science
University of Canterbury
Private Bag 4800, Christchurch
New Zealand.