Create Validate Binary Search Tree

Validate Binary Search Tree

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+# Definition for a binary tree node.
+# class TreeNode:
+#     def __init__(self, val=0, left=None, right=None):
+#         self.val = val
+#         self.left = left
+#         self.right = right
+class Solution:
+    def isValidBST(self, root: Optional[TreeNode]) -> bool:
+
+        def validIt(root, left, right):
+            if root is None:
+                return True 
+
+            if not (root.val > left and root.val < right):
+                return False 
+
+            return (validIt(root.left, left, root.val) and validIt(root.right, root.val, right))
+
+        return validIt(root, float("-inf"), float("inf"))
+
+