LeetCode 0098 - Validate Binary Search Tree

Reck Zhang

发布于 2021-08-11 10:54:09

2510

发布于 2021-08-11 10:54:09

文章被收录于专栏：Reck Zhang

Validate Binary Search Tree

Desicription

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.
Both the left and right subtrees must also be binary search trees.

Example 1:

  2
 / \
1   3

Binary tree [2,1,3], return true.

Example 2:

  1
 / \
2   3

Binary tree [1,2,3], return false.

Solution

/**
 * 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:
    bool isValidBST(TreeNode* root) {
        return isValidBST(root, NULL, NULL);
    }
    bool isValidBST(TreeNode* root, TreeNode* minNode, TreeNode* maxNode) {
        if(!root)
            return 1;
        if((minNode && minNode->val >= root->val) || (maxNode && maxNode->val <= root->val))
            return 0;
        return isValidBST(root->left, minNode, root) && isValidBST(root->right, root, maxNode);
    }
};

本文参与腾讯云自媒体同步曝光计划，分享自作者个人站点/博客。

原始发表：2017-12-15，如有侵权请联系 cloudcommunity@tencent.com 删除

node.js

本文分享自作者个人站点/博客前往查看

如有侵权，请联系 cloudcommunity@tencent.com 删除。

本文参与腾讯云自媒体同步曝光计划，欢迎热爱写作的你一起参与！

node.js

登录后参与评论

0 条评论

热度

LeetCode 0098 - Validate Binary Search Tree

LeetCode 0098 - Validate Binary Search Tree

Validate Binary Search Tree

Desicription

Solution

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐