HashMap 一步到位

//保存原链表节点和复制链表节点的对应
    HashMap<RandomListNode, RandomListNode> hashMap = new HashMap<>();
public RandomListNode Clone(RandomListNode pHead) {
    if (pHead == null)
        return null;
    RandomListNode randomListNode = new RandomListNode(pHead.label);
    hashMap.put(pHead, randomListNode);

    //移动的指针
    RandomListNode temp = randomListNode ;
    RandomListNode cur = pHead;

    while (cur != null) {
    //为next 节点赋值
        if (cur.next != null) {
            if (!hashMap.containsKey(cur.next))
                hashMap.put(cur.next, new RandomListNode(cur.next.label));
            temp.next = hashMap.get(cur.next);
        }
       //为random 节点赋值
        if (cur.random != null) {
            if (!hashMap.containsKey(cur.random))
                hashMap.put(cur.random, new RandomListNode(cur.random.label));
            temp.random = hashMap.get(cur.random);
        }
        //移动指针
        cur = cur.next;
        temp = temp.next;
    }
    return randomListNode;
    }