PriorityQueue.java

public class PriorityQueue<V> implements QueueInterface<V>{

 private NodeBase<V>[] queue;
 private int capacity, currentSize;
	
 //TODO Complete the Priority Queue implementation
 // You may create other member variables/ methods if required.
 @SuppressWarnings("unchecked")
 public PriorityQueue(int capacity) {
 queue=new NodeBase[capacity];
 currentSize=0;
 this.capacity=capacity; 
 }

 public int size() {
 return currentSize;
 }

 public boolean isEmpty() {
 return currentSize<=0;
 }
	
 public boolean isFull() {
 return currentSize>=capacity;
 }

 public void enqueue(Node<V> node) {
 if (isFull())
 return;
 
 int i;
 for (i=0;i<currentSize;i++)
 if (node.getPriority()<queue[i].getPriority())
 break;
 for (int j=currentSize;j>i;j--)
 queue[j]=queue[j-1];
 queue[i]=node;
 currentSize++;
 }

 // In case of priority queue, the dequeue() should 
 // always remove the element with minimum priority value
 public NodeBase<V> dequeue() {
 if (isEmpty())
 return null;

 NodeBase<V> R=queue[0];
 for (int i=1;i<currentSize;i++)
 queue[i-1]=queue[i];
 currentSize--;
 return R;
 }

 public void display () {
	if (this.isEmpty()) {
 System.out.println("Queue is empty");
	}
	for(int i=0; i<currentSize; i++) {
 queue[i+1].show();
	}
 }
}