Dataford
Top 50
Topic roadmap
Updated weekly · Last refresh Sep 13

Top 50 deduplication Interview Questions

The most frequently asked deduplication questions across all roles and companies, ranked by real interview frequency. Updated daily.

50questions
~21htotal time
96companies covered
Track your progressSign up free to work through all 50 questions and resume where you left off.
Start practicing free →
1
CodingStart here. 47 questions · ~1161 min
Longest Substring Without RepeatsMedium
Practice
Recently asked

Use a sliding window and hash map to find the longest substring with no repeated characters in O(n) time.

deduplicationleetcodeArraysBBeaconfiresolutionPrime VideoTTestMu AI
Finding Duplicates in an ArrayMedium
Practice
Recently asked

Use a hash set to find each duplicated array value once in O(n) time.

Hash TablesdeduplicationArraysAutomatic Data ProcessingADPArrow International
Remove Duplicates from ListEasy
Practice
Recently asked

Remove repeated values from a Samsung Semiconductor linked list in place using a runner pointer and constant extra space.

deduplicationLinked ListsSamsung SemiconductorImpact Recruitment GroupRakuten Advertising
Reverse String or Find DuplicatesEasy
Practice
Recently asked

Find the first repeated array element using a set in O(n) time.

deduplicationArraysStringsWebmdWalmart Global TechAvaility
Find Duplicates EfficientlyMedium
Practice
Recently asked

Find repeated values in an array using a hash set with O(n) time complexity.

Hash TablesdeduplicationArraysIrhythm TechnologiesThe Cigna GroupRebellion Defense
Find Kth Duplicate in ArrayMedium
Practice
Recently asked

Find the kth distinct repeated value in encounter order using frequency counting and a second array scan.

Hash TablesdeduplicationArraysHp IqHP SCDSCae
More Coding questions with a free account

Sign up to see every question

Create a free account to unlock this list and practice real interview questions.

Get my prep plan
2
SQL & Data Manipulation3 questions · ~74 min
SQL Duplicate Record DetectionEasy
Practice

Find duplicate American Institutes for Research assessment submissions using a CTE, GROUP BY, HAVING, and joins.

deduplicationsqldata integrityAmerican Institutes for ResearchPublix Super MarketsMacy's
SQL Duplicate Record CleanupMedium
Practice
Recently asked

Identify duplicate transaction rows, retain the earliest record, and delete later duplicates safely.

deduplicationdata cleaningtransactionsOracleDiscoverMicrosoft
More SQL & Data Manipulation questions with a free account
The finish line: interview-readyComplete all 50 questions to finish this plan.