Solution as on 30-09-2022 11:45 pm

Author: knockcat

0098. Validate Binary Search Tree.cpp

@@ -0,0 +1,21 @@
+// 98.✅ Validate Binary Search Tree
+
+class Solution
+{
+public:
+    bool helper(TreeNode *root, long mn, long mx)
+    {
+        if (!root)
+            return true;
+
+        if (root->val <= mn || root->val >= mx)
+            return false;
+
+        return helper(root->left, mn, root->val) && helper(root->right, root->val, mx);
+    }
+
+    bool isValidBST(TreeNode *root)
+    {
+        return helper(root, LONG_MIN, LONG_MAX);
+    }
+};