队列的实现(二) 链式队列的实现

链式队列：使用链表式的节点相连接，所以就不用考虑空间的问题了。

public class QueueList {
    private class Node{
        Node pre,next;
        int value;
    }
    Node front ,rear;
    int a,b;
    int size = 0;
    QueueList(){
        front.next = null;
        front.pre = null;
        front.value = 0;
        rear = front;
    }
    public void add(Node node){
        rear.next = node;
        node.pre = rear;
        rear = node;
        size++;
    }
    public Node remove(){
        if(front == rear)
            return null;
        else{
            Node node = new Node();
            node = front;
            front = front.next;
            size--;
            return node;
        }
    }
    public int size(){
        return size;
    }
}