Dataford
Interview QuestionsInterview GuidesExperiencesMock InterviewsPricing
Get started

Tree Traversal in Python

MediumPython00:00
Practice interviewer
In session
5 left
00:00

Your question is Tree Traversal in Python. Start with the requirements on the right.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

You need to log in / sign up to run or submit.

Problem

HashedIn by Deloitte QA automation workflows may need deterministic traversal results when validating hierarchical test configurations. Given a binary tree, return its pre-order, in-order, and post-order traversals without recursively walking the tree.

Formal Specification

Implement tree_traversals(root). The input root is either None or a nested dictionary with this structure: {"value": integer, "left": node_or_None, "right": node_or_None}. Return a dictionary with three keys: "preorder", "inorder", and "postorder", each containing a list of node values.

Use an iterative algorithm based on an explicit stack. The solution must preserve traversal ordering and should support highly unbalanced trees that may exceed Python's recursion limit.

Constraints

  • The tree contains 0 to 100,000 nodes.
  • Each node value is an integer between -10^9 and 10^9.
  • Each node has at most one left child and one right child.
  • The input is a valid binary tree.

Function Signature

def tree_traversals(root):
Your solutionPython 3
You need to log in / sign up to run or submit.
Run your code to see test output