【递归/迭代】see-94. Binary Tree Inorder Traversal

本文介绍了一种实现二叉树中序遍历的方法,采用迭代方式而非递归方式,利用栈来辅助完成节点的访问顺序。此方法适用于需要高效遍历二叉树结构的场景。

摘要生成于 C知道 ,由 DeepSeek-R1 满血版支持, 前往体验 >

二叉树的中序遍历:

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    vector<int> inorderTraversal(TreeNode* root) {
        vector<int> ans;
        find(ans,root);
        return ans;
    }
    
    void find(vector<int> &ans,TreeNode *root) //迭代
    {
        stack<TreeNode*> rootTemp;
        TreeNode *p=root;
        while(p!=NULL||rootTemp.size()!=0)
        {
            if(p!=NULL)
            {
                rootTemp.push(p);
                p=p->left;
            }
            else
            {
                p=rootTemp.top();
                rootTemp.pop();
                ans.push_back(p->val);
                p=p->right;
            }
        }
    }
    /*
    void find(vector<int> &ans, TreeNode *root) //递归
    {
        if(root==NULL)
            return;
        
        if(root->left)
            find(ans,root->left);
        ans.push_back(root->val);
        if(root->right)
            find(ans,root->right);
        
    }
    */
};

 

American Heritage 题目描述 Farmer John takes the heritage of his cows very seriously. He is not, however, a truly fine bookkeeper. He keeps his cow genealogies as binary trees and, instead of writing them in graphic form, he records them in the more linear tree in-order" and tree pre-order" notations. Your job is to create the `tree post-order" notation of a cow"s heritage after being given the in-order and pre-order notations. Each cow name is encoded as a unique letter. (You may already know that you can frequently reconstruct a tree from any two of the ordered traversals.) Obviously, the trees will have no more than 26 nodes. Here is a graphical representation of the tree used in the sample input and output: C / \ / \ B G / \ / A D H / \ E F The in-order traversal of this tree prints the left sub-tree, the root, and the right sub-tree. The pre-order traversal of this tree prints the root, the left sub-tree, and the right sub-tree. The post-order traversal of this tree print the left sub-tree, the right sub-tree, and the root. ---------------------------------------------------------------------------------------------------------------------------- 题目大意: 给出一棵二叉树的中序遍历 (inorder) 和前序遍历 (preorder),求它的后序遍历 (postorder)。 输入描述 Line 1: The in-order representation of a tree. Line 2: The pre-o rder representation of that same tree. Only uppercase letter A-Z will appear in the input. You will get at least 1 and at most 26 nodes in the tree. 输出描述 A single line with the post-order representation of the tree. 样例输入 Copy to Clipboard ABEDFCHG CBADEFGH 样例输出 Copy to Clipboard AEFDBHGC c语言,代码不要有注释
最新发布
06-16
评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值