434 // Remember:

   434 // Remember:

   435 // - no vars, no ++i, no +=

   435 // - no vars, no ++i, no +=

   436 // - no mutable data-structures (no Arrays, no ListBuffers)

   436 // - no mutable data-structures (no Arrays, no ListBuffers)

   437 

   437 

   438 // But what the heck....lets try to count to 1 Mio in parallel

   438 // But what the heck....lets try to count to 1 Mio in parallel

   439 

   440 

   440 var cnt = 0

   441 var cnt = 0

   441 

   442 

   442 for(i <- (1 to 1000000).par) cnt += 1

   443 for(i <- (1 to 1000000).par) cnt += 1

   443 

   444 

   450 //    two sets?

   451 //    two sets?

   451 // A; IMPROPER WAY (mutable counter)

   452 // A; IMPROPER WAY (mutable counter)

   452 

   453 

   453 def count_intersection(A: Set[Int], B: Set[Int]) : Int = {

   454 def count_intersection(A: Set[Int], B: Set[Int]) : Int = {

   454   var count = 0

   455   var count = 0

   456   count

   457   count

   457 }

   458 }

   458 

   459 

   459 val A = (0 to 999).toSet

   460 val A = (0 to 999).toSet

   460 val B = (0 to 999 by 4).toSet

   461 val B = (0 to 999 by 4).toSet