25、复杂链表的复制

输入一个复杂链表（每个节点中有节点值，以及两个指针，一个指向下一个节点，另一个特殊指针random指向一个随机节点），请对此链表进行深拷贝，并返回拷贝后的头结点。（注意，输出结果中请不要返回参数中的节点引用，否则判题程序会直接返回空）

=================Python=================

# -*- coding:utf-8 -*-
# class RandomListNode:
#     def __init__(self, x):
#         self.label = x
#         self.next = None
#         self.random = None
class Solution:
    # 返回 RandomListNode
    def Clone(self, pHead):
        # write code here
        def dfs(pHead):
            if pHead is None:
                return
            if pHead in visited:
                return visited[pHead]
            node = RandomListNode(pHead.label)
            visited[pHead] = node
            node.next = dfs(pHead.next)
            node.random = dfs(pHead.random)
            return node
        visited = {}
        return dfs(pHead)

================Java================

/*
public class RandomListNode {
    int label;
    RandomListNode next = null;
    RandomListNode random = null;

    RandomListNode(int label) {
        this.label = label;
    }
}
*/
public class Solution {
    public RandomListNode Clone(RandomListNode pHead)
    {
        HashMap<RandomListNode, RandomListNode> map = new HashMap<>();
        RandomListNode cur = pHead;
        while (cur != null) {
            map.put(cur, new RandomListNode(cur.label));
            cur = cur.next;
        }
        
        cur = pHead;
        while (cur != null) {
            map.get(cur).next = map.get(cur.next);
            map.get(cur).random = map.get(cur.random);
            cur = cur.next;
        }
        return map.get(pHead);
    }
}