zoukankan      html  css  js  c++  java
  • [LC] 116. Populating Next Right Pointers in Each Node

    You are given a perfect binary tree where all leaves are on the same level, and every parent has two children. The binary tree has the following definition:
    struct Node {
      int val;
      Node *left;
      Node *right;
      Node *next;
    }
    

    Populate each next pointer to point to its next right node. If there is no next right node, the next pointer should be set to NULL.

    Initially, all next pointers are set to NULL.

    Example:

    Input: {"$id":"1","left":{"$id":"2","left":{"$id":"3","left":null,"next":null,"right":null,"val":4},"next":null,"right":{"$id":"4","left":null,"next":null,"right":null,"val":5},"val":2},"next":null,"right":{"$id":"5","left":{"$id":"6","left":null,"next":null,"right":null,"val":6},"next":null,"right":{"$id":"7","left":null,"next":null,"right":null,"val":7},"val":3},"val":1}
    
    Output: {"$id":"1","left":{"$id":"2","left":{"$id":"3","left":null,"next":{"$id":"4","left":null,"next":{"$id":"5","left":null,"next":{"$id":"6","left":null,"next":null,"right":null,"val":7},"right":null,"val":6},"right":null,"val":5},"right":null,"val":4},"next":{"$id":"7","left":{"$ref":"5"},"next":null,"right":{"$ref":"6"},"val":3},"right":{"$ref":"4"},"val":2},"next":null,"right":{"$ref":"7"},"val":1}
    
    Explanation: Given the above perfect binary tree (Figure A), your function should populate each next pointer to point to its next right node, just like in Figure B.
    

    Note:

    • You may only use constant extra space.
    • Recursive approach is fine, implicit stack space does not count as extra space for this problem.
     1 /*
     2 // Definition for a Node.
     3 class Node {
     4     public int val;
     5     public Node left;
     6     public Node right;
     7     public Node next;
     8 
     9     public Node() {}
    10 
    11     public Node(int _val,Node _left,Node _right,Node _next) {
    12         val = _val;
    13         left = _left;
    14         right = _right;
    15         next = _next;
    16     }
    17 };
    18 */
    19 class Solution {
    20     public Node connect(Node root) {
    21         if (root == null) {
    22             return null;
    23         }
    24         
    25         if (root.left != null) {
    26             root.left.next = root.right;
    27             if (root.next != null) {
    28                 root.right.next = root.next.left;
    29             }
    30         }
    31         connect(root.left);
    32         connect(root.right);
    33         return root;
    34     }
    35 }
  • 相关阅读:
    Java秒杀系统实战系列~整合RabbitMQ实现消息异步发送
    Java秒杀系统实战系列~分布式唯一ID生成订单编号
    Java秒杀系统实战系列~商品秒杀代码实战
    Java秒杀系统实战系列~整合Shiro实现用户登录认证
    Java秒杀系统实战系列~待秒杀商品列表与详情功能开发
    Java秒杀系统实战系列~整体业务流程介绍与数据库设计
    Java秒杀系统实战系列~构建SpringBoot多模块项目
    重磅发布- Java秒杀系统的设计与实战视频教程(SpringBoot版)
    ct
    mysql 分区表
  • 原文地址:https://www.cnblogs.com/xuanlu/p/11757807.html
Copyright © 2011-2022 走看看