Anonymous user
Power set: Difference between revisions
→{{header|Scala}}
Line 2,404:
=={{header|Scala}}==
[[Category:Scala Implementations]]<lang scala>import scala.compat.Platform.currentTime
<lang scala>def powerset[A](s: Set[A]) = s.foldLeft(Set(Set.empty[A])) { case (ss, el) => ss ++ ss.map(_ + el) }</lang>▼
object Powerset extends App {
▲
assert(powerset(Set(1, 2, 3, 4)) == Set(Set.empty, Set(1), Set(2), Set(3), Set(4), Set(1, 2), Set(1, 3), Set(1, 4),
Set(2, 3), Set(2, 4), Set(3, 4), Set(1, 2, 3), Set(1, 3, 4), Set(1, 2, 4), Set(2, 3, 4), Set(1, 2, 3, 4)))
println(s"Successfully completed without errors. [total ${currentTime - executionStart} ms]")
}</lang>
Another option that produces lazy sequence of the sets:
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