zoukankan      html  css  js  c++  java
  • LeetCode Populating Next Right Pointers in Each Node

    Given a binary tree

        struct TreeLinkNode {
          TreeLinkNode *left;
          TreeLinkNode *right;
          TreeLinkNode *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.

    Note:

    • You may only use constant extra space.
    • You may assume that it is a perfect binary tree (ie, all leaves are at the same level, and every parent has two children).

    For example,
    Given the following perfect binary tree,

             1
           /  
          2    3
         /   / 
        4  5  6  7
    

    After calling your function, the tree should look like:

             1 -> NULL
           /  
          2 -> 3 -> NULL
         /   / 
        4->5->6->7 -> NULL
    
     
     
     1 /**
     2  * Definition for binary tree with next pointer.
     3  * public class TreeLinkNode {
     4  *     int val;
     5  *     TreeLinkNode left, right, next;
     6  *     TreeLinkNode(int x) { val = x; }
     7  * }
     8  */
     9 public class Solution {
    10     public void connect(TreeLinkNode root) {
    11             if (root==null) {
    12                 return;
    13             }
    14             TreeLinkNode father=null;
    15             root.next=null;
    16             doConnect(root, father);
    17         
    18     }
    19     
    20     private    void doConnect(TreeLinkNode root,TreeLinkNode father){
    21             if (root == null) {
    22                 return;
    23             }
    24                 TreeLinkNode left=root.left;
    25                 TreeLinkNode right=root.right;            
    26             if (root.left != null) {
    27                 left.next=right;
    28                 if (father !=null) {
    29                     if ((father.next !=null) &&(father.next.left!=null)) {
    30                         right.next=father.next.left;
    31                     }
    32                             
    33                 }
    34                 doConnect(left, left);
    35                 doConnect(right, right);    
    36 
    37             }
    38 
    39     }
    40 }
  • 相关阅读:
    UESTC
    Education Round 8 A
    Gym
    Gym
    hdoj 1159 Common Subsequence
    UVA
    UESTC
    51Nod 1068 Bash游戏 V3 (这规律不好找)
    51Nod 1066 Bash游戏
    51Nod 1002 数塔取数问题
  • 原文地址:https://www.cnblogs.com/birdhack/p/3983560.html
Copyright © 2011-2022 走看看