Merge pull request #5715 from adamcrussell/challenge-153

initial commit

3 files changed, 48 insertions, 0 deletions

diff --git a/challenge-153/adam-russell/blog.txt b/challenge-153/adam-russell/blog.txt
new file mode 100644
index 0000000000..3e0711da3f
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+++ b/challenge-153/adam-russell/blog.txt
@@ -0,0 +1 @@
+http://www.rabbitfarm.com/cgi-bin/blosxom/perl/2022/02/27
diff --git a/challenge-153/adam-russell/perl/ch-1.pl b/challenge-153/adam-russell/perl/ch-1.pl
new file mode 100644
index 0000000000..3e5b1e9a27
--- /dev/null
+++ b/challenge-153/adam-russell/perl/ch-1.pl
@@ -0,0 +1,25 @@
+use strict;
+use warnings;
+##
+# Write a script to determine the first ten members of the Left Factorials sequence.
+##
+use POSIX;
+use constant UPPER_BOUND => INT_MAX/1000;
+
+sub left_factorials_sieve{
+    my($n) = @_;
+    my @sieve = (0 .. UPPER_BOUND);
+    my @left_factorials;
+    my $x = 2;
+    {
+        my @sieve_indices = grep { $_ <= $x || $_ % $x == 0 } 0 .. @sieve - 1; 
+        @sieve = map{ $sieve[$_] } @sieve_indices;
+        $x++;
+        redo if $x <= $n;
+    }
+    return @sieve[1 .. @sieve - 1];
+}
+
+MAIN:{
+    print join(", ", left_factorials_sieve(10)) . "\n";
+}
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diff --git a/challenge-153/adam-russell/perl/ch-2.pl b/challenge-153/adam-russell/perl/ch-2.pl
new file mode 100644
index 0000000000..7ab9492746
--- /dev/null
+++ b/challenge-153/adam-russell/perl/ch-2.pl
@@ -0,0 +1,22 @@
+use strict;
+use warnings;
+##
+# Write a script to figure out if the given integer is a factorion.
+##
+use boolean;
+
+sub factorial{
+    my($n) = @_;
+    return 1 if $n == 1;
+    $n * factorial($n - 1);
+}
+
+sub is_factorion{
+    my($n) = @_;
+    return boolean($n == unpack("%32I*", pack("I*", map {factorial($_)} split(//, $n))));
+}
+
+MAIN:{
+    print is_factorion(145) . "\n";
+    print is_factorion(123) . "\n";
+}
\ No newline at end of file