Binary Tree: Inorder Traversal

来源：互联网发布：淘宝400电话编辑：程序博客网时间：2024/06/05 09:44

11/1

the classic inorder traversal, takes O(n) time and O(1) space

/** * Definition for binary tree * public class TreeNode { *     int val; *     TreeNode left; *     TreeNode right; *     TreeNode(int x) { val = x; } * } */public class Solution {    public List<Integer> inorderTraversal(TreeNode root) {        // The Morris Traversal        List<Integer> ans = new ArrayList<Integer>();        TreeNode p = root;        while(p != null){            if(p.left == null){                ans.add(p.val);                p = p.right;            }else{ // p.left is not null                TreeNode rightM = p.left;                while(rightM.right != null && rightM.right != p){                    rightM = rightM.right;                }                if(rightM.right == null){                    rightM.right = p;                    p = p.left;                }else{                    ans.add(p.val);                    rightM.right = null;                    p = p.right;                }            }        }                return ans;    }}

0 0