LeetCode Validate Binary Search Tree

 // 64ms 过大的
 1 /**
 2  * Definition for binary tree
 3  * struct TreeNode {
 4  *     int val;
 5  *     TreeNode *left;
 6  *     TreeNode *right;
 7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 8  * };
 9  */
10 class Solution {
11 public:
12     bool reVal(int minLeft,TreeNode *root,int maxRight)
13     {
14         int val=root->val;
15         if(val<=minLeft||val>=maxRight)
16             return false;
17         bool leftre=true,rightre=true;
18         if(root->left)
19             leftre=reVal(minLeft,root->left,val);
20         if(leftre==false)
21             return false;
22         if(root->right)
23             rightre=reVal(val,root->right,maxRight);
24         if(rightre==false) 
25             return false;
26         return true;
27     }
28     bool isValidBST(TreeNode *root) {
29         // Start typing your C/C++ solution below
30         // DO NOT write int main() function
31         if(root==NULL)
32             return true;
33         return reVal(-INT_MAX,root,INT_MAX);
34     }
35 };