Create Validate_BST.py

Author: Ram-95

Leetcode_30day_challenge/Validate_BST.py

@@ -0,0 +1,11 @@
+class Solution:
+    def isValidBST(self, root: Optional[TreeNode]) -> bool:
+        MIN = float('-inf')
+        MAX = float('inf')
+        def solve(root, MIN, MAX):
+            if root is None:
+                return True
+            if root.val <= MIN or root.val >= MAX:
+                return False
+            return solve(root.left, MIN, root.val) and solve(root.right,root.val, MAX)
+        return solve(root, MIN, MAX)