作者：David Romano

规范

P15 (**) Replicate the elements of a list a given number of times.

示例

> say prob15(<a b c>, 3);
a a a b b b c c c

源代码：P15-unobe.pl

use v6;

my @l = <a b c>;
sub prob15(@in, $n) {
    gather { for 0 ... @in.end -> $i { for 1 ... $n { take @in[$i] } } }
}
say @l.perl;
say prob15(@l, 3).list.perl;