树的性质推断是树的数据结构比較主要的操作,一般考到都属于非常easy的题目,也就是第一道入门题.面试中最好不能有问题,力求一遍写对.不要给面试官不论什么挑刺机会.LeetCode中关于树的性质有下面题目:Maximum Depth of Binary TreeMinimum Depth of Binary TreeBalanced Binary TreeSame TreeSymmetric Tree 首先说说关于求树的深度的题目,最简单的是求最大深度Maximum Depth of Binary…
树的求和属于树的题目中比較常见的,由于能够有几种变体,灵活度比較高,也能够考察到对于树的数据结构和递归的理解. 一般来说这些题目就不用考虑非递归的解法了(尽管事实上道理是跟LeetCode总结 -- 树的遍历篇一样的.仅仅要掌握了应该没问题哈). LeetCode中关于树的求和有下面题目:Path SumPath Sum IISum Root to Leaf NumbersBinary Tree Maximum Path Sum 我们先来看看最常见的题目Path Sum.这道题是推断是否存在从根…
[94]Binary Tree Inorder Traversal [95]Unique Binary Search Trees II (2018年11月14日,算法群) 给了一个 n,返回结点是 1 - n 的所有形态的BST. 题解:枚举每个根节点 r, 然后递归的生成左右子树的所有集合,然后做笛卡尔积. /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * Tr…
树专题 参考了力扣加加对与树专题的讲解,刷了些 leetcode 题,在此做一些记录,不然没几天就没印象了 力扣加加-树专题 总结 树的定义 // Definition for a binary tree node. public class TreeNode { int val; TreeNode left; TreeNode right; TreeNode(int x) { val = x; } } // Definition for a binary tree node. public c…
Binary Tree Preorder Traversal 题目链接 题目要求: Given a binary tree, return the preorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,2,3]. Note: Recursive solution is trivial, could you do it iteratively? 递…
题目链接 题目要求: Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains only nodes with keys less than the node's key. The right subtree of a node contains only node…
