Proper divisors: Difference between revisions

=={{header|Scala}}==

<lang Scala>def properDivisors(n: Int) = (1 to n/2).filter(i => n % i == 0)

def format(i: Int, divisors: Seq[Int]) = f"$i%5d ${divisors.length}%2d ${divisors mkString " "}"

println(f" n cnt PROPER DIVISORS")

val (count, list) = (1 to 20000).foldLeft( (0, List[Int]()) ) { (max, i) =>

val divisors = properDivisors(i)

if (i <= 10 || i == 100) println( format(i, divisors) )

if (max._1 < divisors.length) (divisors.length, List(i))

else if (max._1 == divisors.length) (divisors.length, max._2 ::: List(i))

else max

}

list.foreach( number => println(f"$number%5d ${properDivisors(number).length}") )</lang>

{{out}}

<pre> n cnt PROPER DIVISORS

1 0

2 1 1

3 1 1

4 2 1 2

5 1 1

6 3 1 2 3

7 1 1

8 3 1 2 4

9 2 1 3

10 3 1 2 5

100 8 1 2 4 5 10 20 25 50

15120 79

18480 79</pre>