剑指 Offer 35.复杂链表的复制

题目描述

问题解析(使用HashMap来做)

1.先判断是否为空，如果为空则返回null
2.新建map集合来进行原始链表到新链表的复制
3.建立新链表的指针指向

代码实例

/* // Definition for a Node. class Node { int val; Node next; Node random; public Node(int val) { this.val = val; this.next = null; this.random = null; } } */
class Solution {
    
    public Node copyRandomList(Node head) {
    
       if(head == null){
    
       		return null;
       }
       Node cur = head;
       Map<Node,Node> map = new HashMap<Node,Node>();
       while(cur != null){
    
       		Map.put(cur,new Node(cur.val));
       		cur = cur.next;
       }
       cur = head;
       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(head);
    }
}