zoukankan      html  css  js  c++  java
  • leetcode--Populating Next Right Pointers in Each Node II

    Follow up for problem "Populating Next Right Pointers in Each Node".

    What if the given tree could be any binary tree? Would your previous solution still work?

    Note:

    • You may only use constant extra space.

    For example,
    Given the following binary tree,

             1
           /  
          2    3
         /     
        4   5    7
    

    After calling your function, the tree should look like:

             1 -> NULL
           /  
          2 -> 3 -> NULL
         /     
        4-> 5 -> 7 -> NULL

    public class Solution {
    	public void connect(TreeLinkNode root) {
    		if(root != null){
    			root.next = null;
    			TreeLinkNode topLevel = root;
    			TreeLinkNode nextLevelHead = null;
    			TreeLinkNode node = null;
    			while(topLevel != null){
    				//looking for the head of next level
    				while(topLevel != null && nextLevelHead == null){
    					if(topLevel.left != null){
    						nextLevelHead = topLevel.left;
    						node = nextLevelHead;
    					}
    					if(topLevel.right != null){
    						if(node == null){
    							nextLevelHead = topLevel.right;
    							node = nextLevelHead;
    						}
    						else{
    							node.next = topLevel.right;
    							node = node.next;
    						}
    					}
    					
    					topLevel = topLevel.next;
    				}
    				
    				while(topLevel != null){
    					if(topLevel.left != null){
    						node.next = topLevel.left;
    						node = node.next;
    					}
    					if(topLevel.right != null){
    						node.next = topLevel.right;
    						node = node.next;
    					}
    					topLevel = topLevel.next;
    				}
    				
    				if(node != null){
    					node.next = null;
    					node = node.next;
    				}
    				topLevel = nextLevelHead;
    				nextLevelHead = null;
    			}
    		}
        }
    }
    

      

  • 相关阅读:
    如何快速转载CSDN及博客园中的博客
    Ubuntu18.04连不网 报"有线连接未托管"
    Ubuntu18.04的网络配置
    vim基本操作
    Git更新远程仓库代码到本地(转)
    POJ 3253 Fence Repair
    POJ 2503 Babelfish
    POJ 2002 Squares
    POJ 1840 Eqs
    POJ 3274 Gold Balanced Lineup
  • 原文地址:https://www.cnblogs.com/averillzheng/p/3769567.html
Copyright © 2011-2022 走看看