classSolution {publicbooleanisValidBST(TreeNode root) {returnisValidBST(root, Integer.MIN_VALUE, Integer.MAX_VALUE); }publicbooleanisValidBST(TreeNode root,intminVal,intmaxVal) {if(root ==null) {returntrue; }if(root.val <= minVal || root.val >=maxVal) {returnfalse; }returnisValidBST(ro...
* TreeNode(int x) : val(x), left(NULL), right(NULL) {} * };*/classSolution {public:boolisValidBST(TreeNode *root,longmn,longmx) {if(!root)returntrue;if(root->val <= mn || root->val >= mx)returnfalse;returnisValidBST(root->left, mn, root->val) && isValidBST(root->righ...
# Definition for a binary tree node. # class TreeNode: # def __init__(self, val=0, left=None, right=None): # self.val = val # self.left = left # self.right = right class Solution: def isValidBST(self, root: Optional[TreeNode]) -> bool: return Solution.dfs(root, None, Non...
https://leetcode.com/problems/validate-binary-search-tree/ 二叉树的问题,要想到递归。这里容易想到的就是如果左右子树都存在,只要 if root.left.val < root.val < root.right.val: return self.isValidBST(root.left) and self.isValidBST(root.right) 1. 2. 但其实不对,看case [10,5,15,null,null...
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 nodes with keys greater than the node’s key...
Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST.According to the definition of LCA on Wikipedia:“The lowest common ancestor is defined between two nodes p and q as the lowest node in T that has both p and q as descendants (wher...
秒了，但只想说：谢谢你！假装是中等题的简单题
第C实现LeetCode108.将有序数组转为二叉搜索树LeetCode 108.Convert Sorted Array to Binary Search Tree 将有序数组转为二叉搜索树 Given an array where e
valid_tic_tac_toe_state_794 docs: update readme Mar 28, 2020 validate_binary_search_tree_98 fix: imports to correct package Mar 28, 2020 verifying_an_alien_dictionary_953 docs: update readme Mar 28, 2020 word_break_139 docs: update readme ...
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 nodes with keys greater than the node's key....