下面是修改后的代码：
public class DoublyList<T> {
public DoubleNode<T> head;
public DoublyList() {
this.head = new DoubleNode<T>();
this.head.prev = null;
this.head.next = null;
}
public String toString() {
String str = this.getClass().getName() + "(";
for (DoubleNode<T> p = this.head.next; p != null; p = p.next)
str += p.data.toString() + ((p.next != null) ? "," : "");
return str + ")";
}
public DoubleNode<T> insert(T x) {
if (x == null)
return null;
DoubleNode<T> rear = head;
while (rear.next != null) {
rear = rear.next;
}
DoubleNode<T> q = new DoubleNode<T>(x, rear, null);
rear.next = q;
return q;
}
public DoublyList(DoublyList<T> list) {
this();
DoubleNode<T> rear = this.head;
for (DoubleNode<T> p = list.head.next; p != null; p = p.next) {
DoubleNode<T> q = new DoubleNode(p.data, rear, null);
rear.next = q;
q.prev = rear;
rear = rear.next;
}
}
public void concat(DoublyList<T> list) {
DoubleNode<T> current1 = this.head.next;
DoubleNode<T> current2 = list.head.next;
while(current1!=null && current1!=this.head){
current1=current1.getNext();
}
while(current2!=null && current2!=list.head){
this.insert(current2.getData());
current2=current2.getNext();
}
}
public void addAll(DoublyList<T> list) {
this.concat(new DoublyList<T>(list));
}
public DoublyList<T> union(DoublyList<T> list) {
DoublyList<T> result = new DoublyList<T>(this);
result.addAll(list);
return result;
}
public static void main(String[] args) {
DoublyList<Integer> list1 = new DoublyList<Integer>();
DoublyList<Integer> list2 = new DoublyList<Integer>();
for (int i = 1; i <= 5; i++)
list1.insert(i);
for (int i = 6; i <= 10; i++)
list2.insert(i);
System.out.println(list1.toString());
System.out.println(list2.toString());
list1.addAll(list2);
System.out.println(list1.toString());
}
}
这样修改后的代码实现了循环双链表和双链表的集合并功能。在concat方法中，我们遍历第二个链表，将每个节点插入到第一个链表末尾；而在addAll方法中，我们创建了一个新的临时链表，并通过调用concat方法将两个链表合并起来；最后，在union方法中，我们先复制原始链表，然后再调用addAll方法将另一个链表添加到复制的链表中。运行代码会输出合并后的结果。
内容由零声教学AI助手提供，问题来源于学员提问
