progs/pow.scala
changeset 669 2f5a4d76756d
parent 650 3031e3379ea3
child 676 62d168bf7ac8
equal deleted inserted replaced
668:9ce78065f68d 669:2f5a4d76756d
     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