# Pandigital multiples

Author: Andrei Osipov

https://projecteuler.net/problem=38

Take the number 192 and multiply it by each of 1, 2, and 3:

192 × 1 = 192 192 × 2 = 384 192 × 3 = 576

By concatenating each product we get the 1 to 9 pandigital, 192384576. We will call 192384576 the concatenated product of 192 and (1,2,3)

The same can be achieved by starting with 9 and multiplying by 1, 2, 3, 4, and 5, giving the pandigital, 918273645, which is the concatenated product of 9 and (1,2,3,4,5).

What is the largest 1 to 9 pandigital 9-digit number that can be formed as the concatenated product of an integer with (1,2, ... , n) where n > 1?

Source code: prob038-andreoss.pl

```use v6;

sub concat-product(\$x, \$n) {
+ [~] do for 1...\$n { \$x * \$_ }
}

sub is-pandigital(Int \$n is copy) {
return unless 123456789 <= \$n <= 987654321;
my \$x = 0;
loop ( ; \$n != 0 ; \$n div=10) {
my \$d = \$n mod 10;
\$x += \$d * 10 ** (9 - \$d);
}
\$x == 123456789;
}

say max gather for 1 .. 9999 -> \$x {
next if \$x !~~ /^^9/;
for 2 .. 5 -> \$n {
my \$l = concat-product \$x, \$n;
take \$l if is-pandigital \$l;
}
}

```