Dataford
Interview QuestionsInterview GuidesExperiencesCoaching
New
Pricing
Get started
Dataford
Popular roles
Software EngineerData AnalystData ScientistData EngineerBusiness AnalystAI EngineerMachine Learning EngineerProduct Manager
Browse
Browse All RolesEvery role hub, from analyst to MLBrowse All CompaniesCompany-specific interview loopsAll Interview GuidesThe full guide library
Top questions by role
Software EngineerData AnalystData ScientistData EngineerBusiness AnalystAI EngineerMachine Learning EngineerProduct Manager
Top questions by skill
SQLPythonStatisticsMachine LearningA/B TestingSystem DesignGenerative AIProduct SenseMetricsBehavioral
Browse all questions →Try a mock interview
Experiences
Practice
Mock InterviewsTimed interview simulations with feedbackCoaching1:1 coaching with people at your target companiesSuccess PathYour 6-week structured planModulesCurated lessons by topicWebinarsTalks from ex-Big Tech data leadsPlaygroundA free-form scratch editor
Learn
BlogInterview strategy and career adviceTech Job Market ReportHiring trends across data and AI rolesFor UniversitiesDataford for career centersAbout DatafordWho we are and how we build
Pricing
Build my plan
Tree Traversal for UI Hierarchy
00:00
5 left

Tree Traversal for UI Hierarchy

MediumPython

Problem

Given a binary tree, write an algorithm to traverse it and find specific nodes representing hierarchical UI elements.

Use def find_ui_nodes(tree, targets):. Represent each node as [value, left, right], with None for a missing child. Return every root-to-node path whose value appears in targets, in preorder traversal order. Include duplicate matching values when they occur at different nodes.

Constraints

  • The tree is either None or a nested node represented as [value, left, right].
  • Each node value is a string.
  • 0 <= number of nodes <= 10^4
  • 0 <= len(targets) <= 10^4
  • Every returned path starts at the root and ends at a matching node.
  • Return matching nodes in preorder traversal order.

Function Signature

def find_ui_nodes(tree, targets):
Interviewer

Your question is Tree Traversal for UI Hierarchy. Start with the requirements in the Question tab.

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.
CodePython 3
Sign up free to run your codeLog inLn 2
Run your code to see test output here.