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
ExperiencesCoaching
New
Practice
Mock InterviewsTimed interview simulations with feedbackSuccess 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
Get started
Build a Scratch App
00:00
5 left

Build a Scratch App

HardPython

Problem

Build an app from scratch, and explain how you would use documentation and references to implement the required features.

For this coding exercise, represent each feature by a name and each documentation reference by the prerequisite features it identifies. Return an order in which all features can be implemented, or an empty list if the references contain a circular dependency.

Input/output contract: features is a list of unique strings. references is a dictionary mapping each feature to a list of prerequisite feature names. Implement build_app_plan(features, references) and return a list of feature names.

Constraints

  • 1 <= len(features) <= 10^4
  • Feature names are unique strings
  • Each prerequisite named in references is also present in features
  • A feature may have zero or more prerequisites
  • Return any valid order when multiple orders exist
  • Return an empty list when the dependency graph contains a cycle

Function Signature

def build_app_plan(features, references):
Interviewer

Your question is Build a Scratch App. 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.
Code
Sign up free to run your codeLog inLn 2
Run your code to see test output here.