스칼라를 사용하여 문자열에 값을 조합하는 방법은 무엇입니까?

Question

문자열의 값을 결합하고 싶습니다.

Let A = a,b,c,d 

내가 같은 조합을 원하는 예를 들어 ,

AComb = a,b,c,d,ab,ac,ad,bc,bd,cd,abc,abd,bcd,acd 

Answer 1

내가 A가 Set

scala> val A =Set("a","b","c","d") 
A: scala.collection.immutable.Set[String] = Set(a, b, c, d) 


scala> val AComb=A.toSet[String].subsets.map(_.mkString).toVector 
AComb: Vector[String] = Vector("", a, b, c, d, ab, ac, ad, bc, bd, cd, abc, abd, acd, bcd, abcd) 

내가 먼저 것을 필요로하지 않는다고 생각하고 있음을 가정하고 요소이므로 시도해보십시오

scala> val AComb=A.toSet[String].subsets.map(_.mkString).toVector.tail 
AComb: scala.collection.immutable.Vector[String] = Vector(a, b, c, d, ab, ac, ad, bc, bd, cd, abc, abd, acd, bcd, abcd) 

scala> val AComb=A.toSet[String].subsets.map(_.mkString).toVector.init.tail 
AComb: scala.collection.immutable.Vector[String] = Vector(a, b, c, d, ab, ac, ad, bc, bd, cd, abc, abd, acd, bcd) 

가

scala> val xc1=Set("sunny","hot","high","FALSE","no") 
xc1: scala.collection.immutable.Set[String] = Set(sunny, FALSE, hot, no, high) 

scala> val AComb=xc1.toSet[String].subsets.map(_.mkString(" ")).toVector.tail; 
AComb: scala.collection.immutable.Vector[String] = Vector(sunny, FALSE, hot, no, high, sunny FALSE, sunny hot, sunny no, sunny high, FALSE hot, FALSE no, FALSE high, hot no, hot high, no high, sunny FALSE hot, sunny FALSE no, sunny FALSE high, sunny hot no, sunny hot high, sunny no high, FALSE hot no, FALSE hot high, FALSE no high, hot no high, sunny FALSE hot no, sunny FALSE hot high, sunny FALSE no high, sunny hot no high, FALSE hot no high)