Each problem shows which companies it is commonly reported at, which data structure it uses and which pattern it teaches — and is solvable in all seven languages.
StructuresArrayBooleanHash MapNumberText
PatternsAccumulatorBest so farBranchingComplement LookupInput and outputIterationJoining textOne-Pass Hash MapRemainder
Reported atAdobeAmazonAppleBloombergGoogleMetaMicrosoft