Java日记2018-05-11

第一题 二叉搜索树与双向链表

https://www.cnblogs.com/edisonchou/p/4793345.html
解题思路待补充

package com.lyc.dataautest;

public class Convert {
    public static BinaryTreeNode Convert(BinaryTreeNode root) {
        BinaryTreeNode last = null;
        convertnode(root,last);
        
        //找到头结点并返回
        BinaryTreeNode headInList = last;
        while (headInList != null && headInList.left != null)
        {
            headInList = headInList.left;
        }

        return headInList;
        
    }
    public static void convertnode(BinaryTreeNode root,BinaryTreeNode lastnode) {
        if(root==null) return;
        BinaryTreeNode current = root;
        //左子树的递归
        if(current.left!=null) {
            convertnode(current.left,lastnode);
        }
        //左子树建立双向链表
        current.left=lastnode;
        if(lastnode!=null) {
            lastnode.right=current;
        }
        //指针迁移，并递归右子树
        lastnode = current;
        if(current.right!=null) {
            convertnode(current.right,lastnode);
        }
        
    }

}