Company OAs DSA Sheet All Problems Placement Data Interview Experiences Premium

Built by students, for students — practice company-specific OAs, DSA sheets, and real interview experiences to land your dream role.

Ready to crack your next OA?

Practice company-specific questions trusted by thousands of students across India.

Start Practicing Go Premium

OA Practice·DSA·Placements

Disclaimer: OAHelper is an independent educational platform. We (oahelper.in) do not own the images or questions shown. Content is uploaded by users.

Topic Difficulty

Hard Combinatorics OA Questions

Practice 26+ hard Combinatorics coding questions from real online assessments. Filter by company, solve in the OAHelper editor, and prepare for company-wise OAs.

All Combinatorics easy medium

String selectionnokiaHard Mega Batch CompletiongoogleHard Question 1linkedinHard Good SequencesamazonHard Question 1 and Question 2microsoft

Hard

Question Compilationuser submittedHard

Encryptiontech mahindraHard

DNA SequencingakamaiHard

Colorful Constructionalgo universityHard

Power of ArraybnyHard

Student ArrangementciscoHard

Count Tree PathsgameskraftHard

Minimum SumadobeHard

Product Dependency TreeintuitHard

K-special numbersuidaiHard

Count of Non-Consecutive ArrangementssiemensHard

Beautiful stringsinfosysHard

Infection SequencesamazonHard

Tech Club Committee FormationmyntraHard

Count Digit Oneamerican expressHard

Tricky subarraysgoogleHard

Tricky SubarraysgoogleHard

Numbers Formation:zomatoHard

Count Digit OneamexHard

Distinct waysnetcoreHard

Palindromic Subsequences of Length 5publicis sapientHard

The coin problemhilabsHard

Numbers and cardsdevrevHard

Card Selection CombinatoricsrapidoHard

Count Grid Coloring PatternsnaviHard

Storage Pair Matchingrubrik 4octHard

Gambler's DicesprinklrHard

Infection SequencesoracleHard

Count Strings with Specific Longest Common Subsequence LengthmyntraHard

Infection SequencesoracleHard

Black and white treeboltearthHard

Count Good ArraysuipathHard

Omega Primesmedianet 5sepHard

Count Palindromic Subsequences of Length 5microsoftHard

Infection SequencesoracleHard

61. DSA: Fault Detection in Automotive FirmwareinfoedgeHard

Infection Sequences CountatlassianHard

Cost of G-Good Setsinfosys 12julyHard

Permutaria Royal DanceinfosysHard

Sum of Beauty of Increasing SubsequencesinfosysHard

Forbidden ArrangementsinfosysHard

Count Valid ArraystrilogyHard

Cost of Lineupsde shawHard

Royal Game MasteradobeHard

nokia OA questions google OA questions linkedin OA questions amazon OA questions microsoft OA questions user submitted OA questions tech mahindra OA questions akamai OA questions

Hard Combinatorics OA Questions | OAHelper