题目：请实现函数clone(ComplexListNode head)复制一个复杂链表。在复杂链表中，每个节点除了有一个next指针指向下一个节点，还有一个sibling指针指向链表中的任意节点或者null。
思路：把问题拆分成三个步骤，第一步先复制所有节点和节点的next，并把复制的节点接在原节点后面，第二步复制节点的sibling，最后再把复制的节点拆分出来。
解决方案：

public class Question35 {
    static class ComplexListNode{
        int value;
        ComplexListNode next;
        ComplexListNode sibling;
        public ComplexListNode(){}
        public ComplexListNode(int value){
            this.value = value;
        }
    }
    public static void cloneNodes(ComplexListNode head){
        ComplexListNode node = head;
        while (node != null){
            ComplexListNode cloned = new ComplexListNode();
            cloned.value = node.value;
            cloned.next = node.next;
            cloned.sibling = node.sibling;
            node.next = cloned;

            node = cloned.next;// 下一个
        }
    }
    public static void connectSiblingNodes(ComplexListNode head){
        ComplexListNode node = head;
        while (node != null){
            ComplexListNode cloned = node.next;
            if (node.sibling != null){
                cloned.sibling = node.sibling.next;
            }
            node = cloned.next;
        }
    }
    public static ComplexListNode reconnectNodes(ComplexListNode head){
        ComplexListNode node = head;
        ComplexListNode clonedHead = null;
        ComplexListNode clonedNode = null;
        if (node != null){
            clonedHead = clonedNode = node.next;
            node.next = clonedNode.next;
            node = node.next;
        }
        while (node != null){
            clonedNode.next = node.next;
            clonedNode = clonedNode.next;
            node.next = clonedNode.next;
            node = node.next;
        }
        return clonedHead;
    }
    public static ComplexListNode clone(ComplexListNode head){
        cloneNodes(head);
        connectSiblingNodes(head);
        return reconnectNodes(head);
    }

    public static void BuildNodes(ComplexListNode pNode, ComplexListNode pNext, ComplexListNode pSibling)
    {
        if(pNode != null)
        {
            pNode.next = pNext;
            pNode.sibling = pSibling;
        }
    }

    public static void main(String[] args) {
        ComplexListNode pNode1 = new ComplexListNode(1);
        ComplexListNode pNode2 = new ComplexListNode(2);
        ComplexListNode pNode3 = new ComplexListNode(3);
        ComplexListNode pNode4 = new ComplexListNode(4);
        ComplexListNode pNode5 = new ComplexListNode(5);

        BuildNodes(pNode1, pNode2, pNode3);
        BuildNodes(pNode2, pNode3, pNode5);
        BuildNodes(pNode3, pNode4, null);
        BuildNodes(pNode4, pNode5, pNode2);

        System.out.println(clone(pNode1).value);
    }
}