LeetCode. Solutions to LeetCode problems in C++, Python, Haskell, APL, Java, Ruby, Rust, Racket, Scala, Kotlin, C#, F#, Clojure, Elixir, Swift, Julia, Smalltalk, Nim, Raku, BQN, Nial, SaC, Futhark, D, Q, J, K, R.