94. 二叉树的中序遍历

给定一个二叉树的根节点 root ，返回它的 中序 遍历。

来源：力扣（LeetCode）
链接：https://leetcode-cn.com/problems/binary-tree-inorder-traversal
著作权归领扣网络所有。商业转载请联系官方授权，非商业转载请注明出处。

import java.util.ArrayList;
import java.util.List;

class Solution {
    public List<Integer> inorderTraversal(TreeNode root) {
        List<Integer> ret = new ArrayList<>();

        TreeNode cur = root;

        while (cur != null) {
            TreeNode mostRight = cur.left;
            if (mostRight != null) {
                while (mostRight.right != null && mostRight.right != cur) {
                    mostRight = mostRight.right;
                }
                if (mostRight.right == null) {
                    mostRight.right = cur;
                    cur = cur.left;
                    continue;
                } else {
                    mostRight.right = null;
                }
            }
            ret.add(cur.val);
            cur = cur.right;
        }


        return ret;
    }
}


class TreeNode {
    int val;
    TreeNode left;
    TreeNode right;

    TreeNode() {
    }

    TreeNode(int val) {
        this.val = val;
    }

    TreeNode(int val, TreeNode left, TreeNode right) {
        this.val = val;
        this.left = left;
        this.right = right;
    }
}

标签：right,TreeNode,cur,val,中序,mostRight,二叉树,94,left
来源： https://www.cnblogs.com/tianyiya/p/15686607.html