/** * Definition for a binary tree node. * type TreeNode struct { * Val int * Left *TreeNode * Right *TreeNode * } */ func isValidBST(root *TreeNode) bool { return dfs(root, nil, nil) } func dfs(root *TreeNode, low *int, high *int) bool { // 空子树必定满足题意 if...
The right subtree of a node contains only nodes with keys greater than the node's key. Both the left and right subtrees must also be binary search trees. 一开始是这样做的: 1classSolution {2public:3boolisValidBST(TreeNode*root) {4returncheckValid(root, INT_MIN, INT_MAX);5}67boolcheck...
1 class Solution { 2 public: 3 bool isValidBST(TreeNode* root)//二叉树的中序遍历 4 { 5 //递归出口 6 if(!root) return true; 7 //搜索二叉树中根结点应小于左子树的最右边节点(左子树最大值),大于右子树的最左边节点(右子树最小值) 8 bool root_valid = false; 9 TreeNode* most_left_...
classSolution{publiclongval=Long.MIN_VALUE;publicbooleanisValidBST(TreeNode root){if(root ==null)returntrue;if(!isValidBST(root.left))returnfalse;if(val >= root.val)returnfalse; val = root.val;return isValidBST(root.right);}}/** * Definition for a binary tree node. * public class...
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 keysless thanthe node's key. The right subtree of a node contains only nodes with keysgreater thanthe node's key. ...
2 * Definition for binary tree 3 * public class TreeNode { 4 * int val; 5 * TreeNode left; 6 * TreeNode right; 7 * TreeNode(int x) { val = x; } 8 * } 9 */ 10 public class Solution { 11 public boolean isValidBST(TreeNode root) { ...
* Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */classSolution{publicbooleanisValidBST(TreeNoderoot){Integermin=null;Integermax=null;returnisValid(root,min,max);}publicbooleanisValid...
* Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */publicclassSolution{public booleanisValidBST(TreeNode root){if(root==null)returntrue;long min=(long)Integer.MIN_VALUE-1;Stack<Tre...
validate(root.right) if right_min <= root.val: self.flag = False return min(left_min, right_min, root.val), max(left_max, right_max, root.val) def isValidBST(self, root: TreeNode) -> bool: if root is None: return True self.flag = True self.validate(root) return self.flag...
root:Optional[TreeNode])->bool:ifrootisNone:# 遍历到最底层returnTrueifnotself.isValidBST(root....