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
First 1 in Sorted Binary Array
00:00
5 left

First 1 in Sorted Binary Array

EasyPython

Problem

Find the first occurrence of 1 in a sorted array of 0s and 1s; then solve it in one iteration.

Asked in the Technical Round 1 stage. Standard binary search was discussed first, followed by the one-iteration solution.

Input and Output

Implement find_first_one(nums), where nums is a non-empty sorted list containing only 0 and 1. Return the zero-based index of the first 1, or -1 if the array contains no 1.

Constraints

  • 1 <= len(nums) <= 1000
  • nums[i] is either 0 or 1
  • nums is sorted in nondecreasing order

Function Signature

def find_first_one(nums):
Interviewer

Your question is First 1 in Sorted Binary Array. 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.