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.
/** * Definition for singly-linked list with a random pointer. * class RandomListNode { * int label; * RandomListNode next, random; * RandomListNode(int x) { this.label = x; } * }; */
【题意】
深拷贝一个链表,链表除了含有next指针外,还包含一个random指针,该指针指向字符串中的某个节点或者为空。
【思路一】(来自网络)
假设原始链表如下,细线表示next指针,粗线表示random指针,没有画出的指针均指向NULL:
构建新节点时,指针做如下变化,即把新节点插入到相应的旧节点后面:
【Java代码】
public class Solution { public RandomListNode copyRandomList(RandomListNode head) { if (head == null) return null; //第一遍扫描:对每个结点进行复制,把复制出来的新结点插在原结点之后 RandomListNode node = head; while (node != null) { RandomListNode newnode = new RandomListNode(node.label); newnode.next = node.next; node.next = newnode; node = newnode.next; } //第二遍扫描:根据原结点的random,给新结点的random赋值 node = head; while (node != null) { if (node.random != null) node.next.random = node.random.next; node = node.next.next; } RandomListNode newhead = head.next; //第三遍扫描:把新结点从原链表中拆分出来 node = head; while (node != null) { RandomListNode newnode = node.next; node.next = newnode.next; if (newnode.next != null) newnode.next = newnode.next.next; node = node.next; } return newhead; } }
【参考】
http://www.cnblogs.com/TenosDoIt/p/3387000.html
http://blog.csdn.net/linhuanmars/article/details/22463599
时间: 2024-10-03 13:27:23