Fixed isValidBST()

Author: soulmachine

C++/chapTree.tex

@@ -1447,15 +1447,15 @@ \subsubsection{分析}
 \subsubsection{代码}
 
 \begin{Code}
-// LeetCode, Validate Binary Search Tree
+// Validate Binary Search Tree
 // 时间复杂度O(n)，空间复杂度O(\logn)
 class Solution {
 public:
     bool isValidBST(TreeNode* root) {
-        return isValidBST(root, INT_MIN, INT_MAX);
+        return isValidBST(root, LONG_MIN, LONG_MAX);
     }
 
-    bool isValidBST(TreeNode* root, int lower, int upper) {
+    bool isValidBST(TreeNode* root, long long lower, long long upper) {
         if (root == nullptr) return true;
 
         return root->val > lower && root->val < upper