Implementing Java Priority Queue
- by Kay
public class PriorityQueue<T> {
private PriorityNode<T> head, tail;
private int numItems;
public PriorityQueue(){
numItems = 0;
head=null;
tail=null;
}
public void add(int priority, T value){
PriorityNode<T> newNode = new PriorityNode<T>(priority,value);
if(numItems == 0){
head = newNode;
tail = newNode;
}
else{
head.setNext(newNode);
head = newNode;
}
}
}
Where PriorityNode is defined as:
public class PriorityNode<T> implements Comparable<T> {
private T value;
private PriorityNode<T> next;
private int priority;
public PriorityNode(int priority,T newValue){
value = newValue;
next = null;
priority = 0;
}
public PriorityNode(T newValue){
value = newValue;
next = null;
priority = 0;
}
public void setPriority(int priority){
this.priority = priority;
}
public int getPriority(){
return this.priority;
}
public T getValue(){
return value;
}
public PriorityNode<T> getNext(){
return next;
}
public void setNext(PriorityNode<T> nextNode){
this.next = nextNode;
}
public void setValue(T newValue){
value = newValue;
}
public int compareTo(int pri) {
// TODO Auto-generated method stub
if(this.priority<pri){
return -1;
}
else if(this.priority == pri){
return 0;
}
else{
return 1;
}
}
}
I'm having a lot of difficulty using the Comparator here and implementing a priority queue - please point me in the right direction.
