算法题LC13：copy-list-with-random-pointer

链表：
题目描述：
现在有一个这样的链表：链表的每一个节点都附加了一个随机指针，随机指针可能指向链表中的任意一个节点或者指向空。
请对这个链表进行深拷贝。
A linked list is given such that each node contains an additional random pointer which could point to any node in the list or null.
Return a deep copy of the list.
输入描述：

输出描述：

示例1：
输入：

输出：
        
代码：

import java.util.*;
/**
 * Definition for singly-linked list with a random pointer.
 * class RandomListNode {
 *     int label;
 *     RandomListNode next, random;
 *     RandomListNode(int x) { this.label = x; }
 * };
 */
public class Solution {
    public RandomListNode copyRandomList(RandomListNode head) {
        if(head == null )
            return null;
        Map<RandomListNode,RandomListNode> map = new HashMap<>();
        RandomListNode p = head;
        RandomListNode nex = head.next;
        while(p!=null)
        {
            RandomListNode newNode = new RandomListNode(p.label);
            newNode.next = nex;
            map.put(p,newNode);
            p = nex;
            if(nex != null)
                nex = nex.next;
        }
         
        for(RandomListNode old : map.keySet())
        {
            RandomListNode newNode = map.get(old);
            if(old.random != null)
            {
                newNode.random = map.get(old.random);
                map.put(old,newNode);
            }
        }
        return map.get(head);
    }
}

标签：map,copy,random,list,RandomListNode,nex,newNode,null
来源： https://blog.csdn.net/alidingding/article/details/104673060