Leetcode accepted

PriyankaKhire · web-flow · commit 07a80a25412e · 2021-08-26T12:40:53.000-07:00
diff --git a/Blind 75/Programs/Validate Binary Search Tree.py b/Blind 75/Programs/Validate Binary Search Tree.py
@@ -0,0 +1,34 @@
+# Validate Binary Search Tree
+# https://leetcode.com/problems/validate-binary-search-tree/
+
+# Definition for a binary tree node.
+# class TreeNode(object):
+#     def __init__(self, val=0, left=None, right=None):
+#         self.val = val
+#         self.left = left
+#         self.right = right
+class Solution(object):
+    # inorder traversal of BST is alwasy sorted in ascending order.
+    def inOrder(self, node, traversal):
+        if not node:
+            return
+        self.inOrder(node.left, traversal)
+        traversal.append(node.val)
+        self.inOrder(node.right, traversal)
+    
+    # validate if the traversal is in ascending order or not.
+    def validate(self, traversal):
+        for i in range(1, len(traversal)):
+            if (traversal[i-1] >= traversal[i]):
+                return False
+        return True
+        
+    def isValidBST(self, root):
+        traversal = []
+        self.inOrder(root, traversal)
+        return self.validate(traversal)
+        """
+        :type root: TreeNode
+        :rtype: bool
+        """
+        
