progs/pow.scala
changeset 669 e22b5faa7e66
parent 650 b34efa58f7d5
child 676 41fee9bd4150
equal deleted inserted replaced
668:2cc6d223d5b4 669:e22b5faa7e66
     3 
     3 
     4 def pow(A: Set[String], n: Int) : Set[String] = n match {
     4 def pow(A: Set[String], n: Int) : Set[String] = n match {
     5   case 0 => Set("")
     5   case 0 => Set("")
     6   case n => concat(A, pow(A, n- 1))
     6   case n => concat(A, pow(A, n- 1))
     7 }
     7 }
       
     8 
       
     9 val A = Set("aa", "aaa")
       
    10 val B = Set("aaa", "aa")
       
    11 concat(A, B).size                     // -> 28 
       
    12 
       
    13 
     8 
    14 
     9 val A = Set("1", "2", "3", "")
    15 val A = Set("1", "2", "3", "")
    10 val B = Set("1", "2", "3", "4", "5", "6", "")
    16 val B = Set("1", "2", "3", "4", "5", "6", "")
    11 concat(A, B).size                     // -> 28 
    17 concat(A, B).size                     // -> 28 
    12 pow(B, 3).size 
    18 pow(B, 3).size