我希望将字符串中的数值合并。例如:
Let A = a,b,c,d
我希望将它们组合成以下形式:
AComb = a,b,c,d,ab,ac,ad,bc,bd,cd,abc,abd,bcd,acd
我希望将字符串中的数值合并。例如:
Let A = a,b,c,d
我希望将它们组合成以下形式:
AComb = a,b,c,d,ab,ac,ad,bc,bd,cd,abc,abd,bcd,acd
A
是一个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)
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)
删除第一个和最后一个元素
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)
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)
A = a,b,c,d
?应该是val A = Set("a", "b", "c", "d")
吧? - Govind Singh