Data Structures · Question 12 · Hard
The preorder traversal of a Binary Search Tree is 50, 30, 20, 40, 70, 60, 80. What is its postorder traversal?
- 20, 30, 40, 50, 60, 70, 80
- 20, 40, 30, 50, 60, 80, 70
- 40, 20, 30, 80, 60, 70, 50
- 20, 40, 30, 60, 80, 70, 50
Answer and explanation
Answer: D. 20, 40, 30, 60, 80, 70, 50
Explanation: The root is 50; the left subtree is 30 with children 20 and 40; the right subtree is 70 with children 60 and 80. Postorder (left, right, root) gives 20, 40, 30, 60, 80, 70, 50.
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