今天分享的题目来源于 LeetCode 第 105 号问题:重建二叉树。 题目链接:https://leetcode-cn.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/ 一、题目描述 输入某二叉树的前序遍历和中序遍历的结果,请重建该二叉树。假设输入的前序遍历和中序遍历的结果中都不含重复的数字。 例如,给...
link:[https://leetcode.com/explore/learn/card/data-structure-tree/134/traverse-a-tree/928/] 递归解法: #Definition for a binary tree node.#class TreeNode(object):#def __init__(self, x):#self.val = x#self.left = None#self.right = NoneclassSolution(object):defsolve(self,root):ifroo...
https://leetcode.com/problems/binary-tree-postorder-traversal/ Given a binary tree, return thepostordertraversal of its nodes' values. For example: Given binary tree{1,#,2,3}, 1 \ 2 / 3 return[3,2,1]. Note:Recursive solution is trivial, could you do it iteratively? 后续遍历二叉树,...
Left != nil || root.Right != nil { return root } // 此时当前子树中的所有子结点都是 0 ,需要修剪掉 return nil } 题目链接: Binary Tree Pruning: leetcode.com/problems/b 二叉树剪枝: leetcode.cn/problems/bi LeetCode 日更第 235 天,感谢阅读至此的你 欢迎点赞、收藏鼓励支持小满...
力扣leetcode-cn.com/problems/diameter-of-binary-tree/ 题目描述 给定一棵二叉树,你需要计算它的直径长度。一棵二叉树的直径长度是任意两个结点路径长度中的最大值。这条路径可能穿过也可能不穿过根结点。 示例: 给定二叉树 1 / \ 2 3 / \ 4 5 返回3, 它的长度是路径 [4,2,1,3] 或者 [5...
226. Invert Binary Tree 提交网址:https://leetcode.com/problems/invert-binary-tree/ Total Accepted:84040Total Submissions:186266Difficulty:EasyACrate:45.1% Invert a binary tree. 4 / \ 2 7 / \ / \ 1 3 6 9 to 4 / \ 7 2 / \ / \ 9 6 3 1 ...
https://leetcode.com/problems/balanced-binary-tree/ 题目: Given a binary tree, determine if it is height-balanced. every 思路: 根据结点高度,递归判断是否满足平衡树定义。此题跟Kth Smallest Element in a BST做法类似,在遍历过程中遇到满足某条件的结点时,将结果放到全局变量中,如果没遇到最终递归返回的...
// 方案2 “官方,递归法。(本质:跟方案1的思路是一致的,只是少了1次树的遍历 —— getMaxValByNewTree)”。// 参考:// 1)https://leetcode-cn.com/problems/binary-tree-maximum-path-sum/solution/er-cha-shu-zhong-de-zui-da-lu-jing-he-by-leetcode-/// 思路:// 1)状态初始化:resVal = Nu...
* Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode() : val(0), left(nullptr), right(nullptr) {} * TreeNode(int x) : val(x), left(nullptr), right(nullptr) {} ...
-3000 <= preorder[i], inorder[i] <= 3000 inorder 均出现在 preorder preorder 保证 为二叉树的前序遍历序列 inorder 保证 为二叉树的中序遍历序列 注意:本题与主站 105 题重复:https://leetcode-cn.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/通过...