Largest palindrome product: Difference between revisions
Content added Content deleted
Thundergnat (talk | contribs) (→{{header|Raku}}: use external library for 25x speedup (still slow, but not dreadful)) |
SqrtNegInf (talk | contribs) (Added Perl) |
||
Line 73: | Line 73: | ||
Largest palindromic product of two 9-digit integers: 999980347 x 999920317 = 999900665566009999 |
Largest palindromic product of two 9-digit integers: 999980347 x 999920317 = 999900665566009999 |
||
</pre> |
</pre> |
||
=={{header|Perl}}== |
|||
{{libheader|ntheory}} |
|||
<lang perl>use strict; |
|||
use warnings; |
|||
use feature 'say'; |
|||
use ntheory 'divisors'; |
|||
for my $l (2..7) { |
|||
LOOP: |
|||
for my $p (sort { $b <=> $a } map { $_ . reverse $_ } 10**($l-1) .. 10**$l - 1) { |
|||
my @f = sort { $b <=> $a } grep { length == $l } divisors $p; |
|||
next unless @f >= 2 and $p == $f[0] * $f[1]; |
|||
say "Largest palindromic product of two @{[$l]}-digit integers: $f[1] × $f[0] = $p" and last LOOP; |
|||
} |
|||
}</lang> |
|||
{{out}} |
|||
<pre>Largest palindromic product of two 2-digit integers: 91 × 99 = 9009 |
|||
Largest palindromic product of two 3-digit integers: 913 × 993 = 906609 |
|||
Largest palindromic product of two 4-digit integers: 9901 × 9999 = 99000099 |
|||
Largest palindromic product of two 5-digit integers: 99681 × 99979 = 9966006699 |
|||
Largest palindromic product of two 6-digit integers: 999001 × 999999 = 999000000999 |
|||
Largest palindromic product of two 7-digit integers: 9997647 × 9998017 = 99956644665999</pre> |
|||
=={{header|Raku}}== |
=={{header|Raku}}== |