Social & Media

X (Twitter) interview questions

Grouped by topic, sorted Easy → Medium → Hard, then by LeetCode ID. Click a problem to open it on LeetCode; the chapter column links to the handbook chapter that covers it.

Problems
50
Easy
8
Medium
30
Hard
12
Mapped to chapter
20

Array

20 problems

Easy 2

118Pascal's Trianglealso at:AdobeAirtelAmazon Also at 4 moreBloombergGoogleMetaMicrosoft Easy—
2073Time Needed to Buy Ticketsalso at:Google Easy—

Medium 11

56Merge Intervalsalso at:SnapAdobeAirtel Also at 46 moreAmazonAMDAppleAtlassianAutodeskBloombergByteDanceCars24CiscoCitadelCrowdStrikeDatabricksDocuSignDoorDashDropboxeBayExpediaFlipkartGoldman SachsGoogleInstacartJuspayMetaMicrosoftMorgan StanleyNetflixOktaOYOPalantirPayPalPhonePeQualcommRazorpayRipplingRobloxSAPTargetTeslaToastUberVisaVMwareWalmart Global TechYelpZohoZomato MediumChapter
251Flatten 2D Vectoralso at:AirbnbLyft Medium—
378Kth Smallest Element in a Sorted Matrixalso at:AdobeChimeMeta Also at 3 moreMicrosoftNianticPhonePe Medium—
380Insert Delete GetRandom O(1)also at:SnapAdobeAmazon Also at 20 moreAppleBloombergCars24CiscoCitadelDocuSignDoorDashGoogleIntuitLinkedInMicrosoftNetflixOktaOYORobloxSamsaraTwilioUberVMwareYelp MediumChapter
764Largest Plus Signalso at:Intuit Medium—
1167Minimum Cost to Connect SticksMediumChapter
1785Minimum Elements to Add to Form a Given SumMedium—
1817Finding the Users Active MinutesMedium—
1882Process Tasks Using Serversalso at:Google Medium—
1905Count Sub Islandsalso at:DoorDash Medium—
2768Number of Black Blocksalso at:BlockRobloxStripe Medium—

Hard 7

42Trapping Rain Wateralso at:AdobeAirbnbAmazon Also at 34 moreAtlassianBloombergByteDanceCitadelCrowdStrikeDocuSigneBayFlipkartGoldman SachsGoogleGrowwInMobiIntelIntuitLyftMetaMicrosoftMyntraNaviNVIDIAOpenAIPayPalPaytmPhonePeQualcommRakutenRobloxSAPSnowflakeSwiggyTeslaUrban CompanyWalmart Global TechZoho HardChapter
140Word Break IIalso at:SnapAmazonBloomberg Also at 5 moreDropboxeBayGoogleMicrosoftMongoDB HardChapter
149Max Points on a Linealso at:AmazonCiscoCitadel Also at 3 moreGoogleLinkedInMeesho HardChapter
218The Skyline Problemalso at:AdobeCitadelGoogle Also at 2 moreYelpZomato HardChapter
269Alien Dictionaryalso at:SnapAirbnbAmazon Also at 7 moreBloombergCitadelGoogleMetaUberVMwareZoom HardChapter
296Best Meeting Pointalso at:DoorDashLinkedIn Hard—
407Trapping Rain Water IIalso at:AmazonByteDanceFlipkart Also at 3 moreGoogleMicrosoftQualcomm Hard—

Hash Table

9 problems

Easy 1

202Happy Numberalso at:AdobeAirbnbAmazon Also at 9 moreBloombergCiscoeBayGoogleMetaMicrosoftPayPalSnowflakeSwiggy EasyChapter

Medium 8

12Integer to Romanalso at:AdobeAmazonAMD Also at 9 moreAtlassianBloombergCitadelDocuSignDoorDashGoogleMetaMicrosoftSwiggy Medium—
146LRU Cache★ also at:LINERedditSnap Also at 59 moreSpotifyAdobeAmazonAMDAppleArista NetworksAutodeskBloombergByteDanceCiscoCitadelCloudflareCREDDelhiveryDocuSignDoorDasheBayExpediaFlipkartGoogleGrowwIntelIntuitJane StreetJPMorganLinkedInLyftMetaMicrosoftMongoDBMorgan StanleyMyntraNetflixNianticNVIDIANykaaOktaOlaPalantirPayPalPhonePeQualcommRakutenRazorpayRipplingSalesforceSAPSnowflakeSplunkSwiggyTargetTeslaToastTwilioUberVisaVMwareZoomZscaler MediumChapter
208Implement Trie (Prefix Tree)★ also at:AmazonAppleBlock Also at 10 moreBloombergCitadelDocuSignDoorDasheBayGoogleMetaMicrosoftMongoDBRoblox MediumChapter
355Design Twitter★ also at:AmazonMeeshoMicrosoft Also at 3 morePayPalSalesforceSwiggy MediumChapter
433Minimum Genetic Mutationalso at:Google Medium—
1347Minimum Number of Steps to Make Two Strings Anagramalso at:BloombergDoorDash Medium—
1348Tweet Counts Per FrequencyMedium—
1797Design Authentication Manageralso at:DeliverooDocuSignMicrosoft MediumChapter

Database

6 problems

Easy 2

586Customer Placing the Largest Number of Ordersalso at:GoogleMicrosoft Easy—
1683Invalid Tweetsalso at:Google Easy—

Medium 4

580Count Student Number in DepartmentsMedium—
585Investments in 2016also at:GoogleMeta Medium—
608Tree NodeMedium—
1459Rectangles AreaMedium—

String

6 problems

Easy 1

20Valid Parentheses★ also at:SpotifyAdobeAirbnb Also at 36 moreAmazonAutodeskBloombergCiscoCoinDCXCrowdStrikeDelleBayEpic SystemsFlipkartFreshworksGoogleGrowwIntelIntuitJane StreetJioLinkedInLyftMetaMicrosoftNetflixNVIDIAPayPalPaytmPhonePeQualcommRobloxSAPSplunkSwiggyTargetTeslaToastTwilioVMware EasyChapter

Medium 3

468Validate IP Addressalso at:Google Medium—
831Masking Personal InformationMedium—
1910Remove All Occurrences of a Substringalso at:Arista Networks Medium—

Hard 2

10Regular Expression Matchingalso at:AdobeAirbnbAmazon Also at 11 moreAppleBloombergByteDanceCitadeleBayGoogleLyftMetaMicrosoftPhonePeZoho Hard—
44Wildcard Matchingalso at:SnapAdobeAmazon Also at 8 moreBloombergByteDanceGoogleInMobiInstacartMicrosoftTwo SigmaZoho Hard—

Linked List

3 problems

Easy 1

206Reverse Linked List★ also at:LINESnapSpotify Also at 19 moreAdobeAmazonAppleBloombergByteDanceCiscoeBayGoogleGrowwJioLinkedInMetaMicrosoftPaytmQualcommSAPTeslaVMwareYelp EasyChapter

Hard 2

23Merge k Sorted Lists★ also at:AdobeAirbnbAmazon Also at 25 moreAppleBloombergByteDanceCiscoCitadelCloudflareDeliverooDocuSignDoorDasheBayFlipkartGoogleLyftMetaMicrosoftMongoDBNianticNVIDIANykaaOlaPalantirQualcommRipplingTwo SigmaVMware HardChapter
1206Design Skiplistalso at:eBay HardChapter

Misc

6 problems

Easy 1

868Binary Gapalso at:AmazoneBayGoogle Also at 1 moreMicrosoft EasyChapter

Medium 4

43Multiply Stringsalso at:PinterestAmazonCleartrip Also at 3 moreGoogleTwo SigmaZoho Medium—
161One Edit Distancealso at:SnapStripe MediumChapter
235Lowest Common Ancestor of a Binary Search Treealso at:AdobeAmazonGoogle Also at 1 moreMicrosoft MediumChapter
341Flatten Nested List Iteratoralso at:AmazonAppleeBay Also at 6 moreLyftNetflixOpenAISplunkTeslaVMware Medium—

Hard 1

60Permutation Sequencealso at:AmazonGoogle Hard—