A O(n) Scala one: https://github.com/pathikrit/scalgos/blob/master/src/main/scala/com/github/pathikrit/scalgos/Combinatorics.scala#L100 https://github.com/pathi

A O(n) Scala one: https://github.com/pathikrit/scalgos/blob/master/src/main/scala/com/github/pathikrit/scalgos/Combinatorics.scala#L100 https://github.com/pathikrit/scalgos/blob/master/src/main/sc...