作者：David Romano

规范

P17 (*) Split a list into two parts; the length of the first part is given.
  Do not use any predefined predicates.

示例

> say bisect(<a b c d e f g h i k>, 3).perl
(["a", "b", "c"], ["d", "e", "f", "g", "h", "i", "k"])

源代码：P17-unobe.pl

use v6;

my @l = <a b c d e f g h i k>;
sub prob17(@in, $n) {
    if @in.end < $n { return @in }
    else {
        my $beg = [gather { for 0...$n-1 { take @in[$_] } }];
        my $end = [gather { for [email protected]  { take @in[$_] } }];
        return ($beg, $end);
    }
}
say @l.perl;
say prob17(@l, 3).perl;