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
Implement K-Means in Python
00:00
5 left

Implement K-Means in Python

MediumPython

Problem

Vectra AI can group similar network-security alerts by feature vectors to support downstream investigation. Implement one-dimensional-independent k-means clustering for a small batch of alert vectors.

Given points, an initial list of k centroids, and a maximum iteration count, repeatedly assign every point to its nearest centroid and recompute each centroid as the coordinate-wise mean of its assigned points.

Formal Specification

Implement kmeans(points, initial_centroids, max_iterations). points is a non-empty list of equal-length numeric vectors. initial_centroids contains k equal-length numeric vectors, where 1 <= k <= len(points). Return a dictionary with:

  • labels: a list of length len(points), where each value is the assigned centroid index.
  • centroids: the final list of k coordinate-wise mean vectors.

Use squared Euclidean distance. If a point is equally close to multiple centroids, assign it to the lowest index. If a centroid receives no points during an iteration, leave it unchanged. Stop early when no centroid coordinate changes, or after max_iterations iterations.

Constraints

  • 1 <= len(points) <= 1,000
  • 1 <= len(initial_centroids) <= len(points)
  • All vectors have the same positive dimension, at most 20
  • Feature values are integers or floating-point numbers
  • 1 <= max_iterations <= 100

Function Signature

def kmeans(points, initial_centroids, max_iterations):
Interviewer

Your question is Implement K-Means in Python. 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.