Social & Media

Reddit 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
18
Easy
6
Medium
10
Hard
2
Mapped to chapter
10

Array

6 problems

Easy 1

706Design HashMapalso at:AdobeAmazonMeta Also at 5 moreMicrosoftRakutenSnowflakeTwo SigmaVMware Easy—

Medium 5

162Find Peak Elementalso at:SnapAmazonBloomberg Also at 14 moreByteDanceDatabricksDocuSignFlipkartFreshworksGoogleGrowwLyftMetaMicrosoftPayPalUberUrban CompanyVMware MediumChapter
200Number of Islands★ also at:PinterestSnapSpotify Also at 43 moreAdobeAmazonAMDAppleAutodeskBloombergByteDanceCapital OneCiscoCitadelCloudflareCREDCrowdStrikeDocuSignDoorDashDropboxeBayFlipkartGoldman SachsGoogleIntelIntuitLinkedInLyftMeeshoMetaMicrosoftOktaOlaPayPalPhonePeQualcommSAPSplunkTargetTeslaToastUberUrban CompanyVMwareWalmart Global TechZohoZomato MediumChapter
286Walls and Gatesalso at:SpotifyByteDanceDoorDash Also at 4 moreGoogleMetaNianticSamsara Medium—
289Game of Lifealso at:SnapDropboxMeta Also at 1 moreTwo Sigma Medium—
362Design Hit Counter★ also at:AppleAtlassianBloomberg Also at 9 moreCloudflareDatabricksDeliverooDropboxGoogleMetaOpenAIRobloxUber MediumChapter

Hash Table

6 problems

Easy 2

13Roman to Integeralso at:AdobeAmazonAMD Also at 8 moreBloombergDoorDashGoldman SachsGoogleInMobiMetaMicrosoftRakuten Easy—
359Logger Rate Limiteralso at:AmazonAtlassianCloudflare Also at 6 moreDeliverooDocuSignGoogleIntuitNetflixRoblox EasyChapter

Medium 2

146LRU Cache★ also at:LINESnapSpotify Also at 59 moreX (Twitter)AdobeAmazonAMDAppleArista NetworksAutodeskBloombergByteDanceCiscoCitadelCloudflareCREDDelhiveryDocuSignDoorDasheBayExpediaFlipkartGoogleGrowwIntelIntuitJane StreetJPMorganLinkedInLyftMetaMicrosoftMongoDBMorgan StanleyMyntraNetflixNianticNVIDIANykaaOktaOlaPalantirPayPalPhonePeQualcommRakutenRazorpayRipplingSalesforceSAPSnowflakeSplunkSwiggyTargetTeslaToastTwilioUberVisaVMwareZoomZscaler MediumChapter
314Binary Tree Vertical Order Traversalalso at:LINESnapAdobe Also at 5 moreAppleBloombergByteDanceDoorDashMeta Medium—

Hard 2

127Word Ladderalso at:SnapSpotifyAmazon Also at 15 moreAppleBloombergDocuSignFlipkartGoogleLinkedInLyftMetaMicrosoftOktaPhonePeUberVMwareYelpZscaler HardChapter
987Vertical Order Traversal of a Binary Treealso at:AdobeAmazonBloomberg Also at 6 moreDeliverooDoorDashGoogleMetaMicrosoftUber Hard—

Misc

6 problems

Easy 3

21Merge Two Sorted Lists★ also at:SnapAdobeAmazon Also at 24 moreArista NetworksBloombergByteDanceCars24CleartripCoinDCXDelhiveryDocuSigneBayFlipkartFreshworksGoogleIntuitLyftMetaMicrosoftMongoDBQualcommRakutenRevolutRipplingSwiggyVMwareZoho EasyChapter
100Same Treealso at:AmazonBloombergGoogle Also at 6 moreLinkedInMetaMicrosoftSAPWiseZoom EasyChapter
338Counting Bits★ also at:AmazonQualcomm EasyChapter

Medium 3

227Basic Calculator IIalso at:SnapAirbnbAmazon Also at 9 moreAppleBloombergDoorDasheBayExpediaGoogleMetaTeslaUber MediumChapter
1218Longest Arithmetic Subsequence of Given DifferenceMedium—
2240Number of Ways to Buy Pens and PencilsMedium—