www.pudn.com > fp_growth_source.rar > Queue.java

package association.fptree; 
 
/** 
 * 树广度遍历的辅助队列,尾进头出； 
 * */ 
class Queue{ 
	Elem head,tail,elem; 
	//void in(FPTree.Node node){ 
	void in(T node){ 
		elem=new Elem(node); 
		if ((head==null)&&(tail==null)){ 
		    tail=elem; 
		    head=elem; 
		}     
		else{ 
			tail.next=elem; 
			tail=elem; 
		}	 
	} 
	//FPTree.Node out(){ 
	T out(){ 
		Elem e; 
		if ((head==null)&&(tail==null)){ 
			return null; 
		} 
		else if(head==tail){ 
			e=head; 
			head=tail=null; 
		    return e.node; 
		} 
		else{ 
			e=head; 
			head=head.next; 
		    return e.node; 
		} 
	} 
	boolean IsEmpty(){ 
		if ((head==null)&&(tail==null)){ 
			return true; 
		} 
		return false; 
	} 
	/** 
	 * 清空队列 
	 * */ 
	void Empty(){ 
		head=null; 
		tail=null; 
	} 
	Queue(){ 
		head=null; 
		tail=null; 
		 
		 
	} 
	class Elem{ 
		//FPTree.Node node; 
		T node; 
		Elem next; 
		//Elem(FPTree.Node node){ 
		Elem(T node){ 
			this.node=node; 
			next=null; 
		} 
	}	 
}