add second challenge

1 files changed, 44 insertions, 0 deletions

diff --git a/challenge-066/3ter/ch-2.pl b/challenge-066/3ter/ch-2.pl
new file mode 100644
index 0000000000..c1258b6253
--- /dev/null
+++ b/challenge-066/3ter/ch-2.pl
@@ -0,0 +1,44 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+use v5.30;
+
+my ($int) = @ARGV;
+die 'Please provide one integer e.g. \'ch-2.pl 9\''
+  if ( !defined($int) );
+
+say power_integers($int);
+
+sub power_integers {
+    my ($int) = @_;
+
+    my ( $factor, $power ) = get_factor_and_power($int);
+    if ( defined($power) and $power > 0 ) {
+        return $factor . '^' . $power;
+    }
+    else {
+        return 0;
+    }
+}
+
+sub get_factor_and_power {
+    my ($int) = @_;
+
+    # try those factors naively
+    my $factor;
+    my $max_factor = int( sqrt($int) );
+    foreach my $potential_factor ( 2 .. $max_factor ) {
+        if ( $int % $potential_factor == 0 ) {
+            $factor = $potential_factor;
+
+            # verify that the factor is powerful enough
+            my $power = 1;
+            while ( $factor**$power < $int ) {
+                $power++;
+            }
+            return ( $factor, $power ) if ( $factor**$power == $int );
+        }
+    }
+    return 0;
+}
+