sgreen solution to challenge 133

4 files changed, 78 insertions, 2 deletions

diff --git a/challenge-133/sgreen/README.md b/challenge-133/sgreen/README.md
index 0022b09d87..298af3387e 100644
--- a/challenge-133/sgreen/README.md
+++ b/challenge-133/sgreen/README.md
@@ -1,3 +1,3 @@
-# The Weekly Challenge 131
+# The Weekly Challenge 133
 
-Solution by Simon Green. [Blog](https://dev.to/simongreennet/weekly-challenge-131-1fl1)
+Solution by Simon Green. [Blog](https://dev.to/simongreennet/weekly-challenge-133-7gi)
diff --git a/challenge-133/sgreen/blog.txt b/challenge-133/sgreen/blog.txt
new file mode 100644
index 0000000000..130dbc3790
--- /dev/null
+++ b/challenge-133/sgreen/blog.txt
@@ -0,0 +1 @@
+https://dev.to/simongreennet/weekly-challenge-133-7gi
diff --git a/challenge-133/sgreen/perl/ch-1.pl b/challenge-133/sgreen/perl/ch-1.pl
new file mode 100755
index 0000000000..4033f28040
--- /dev/null
+++ b/challenge-133/sgreen/perl/ch-1.pl
@@ -0,0 +1,22 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+
+sub main {
+    my $N = shift;
+
+    # Sanity check
+    die "You must specify a positive integer\n"               unless defined $N;
+    die "The value doesn't appear to be a positive integer\n" unless $N =~ /^[1-9][0-9]*$/;
+
+    # We do this the crude way
+    my $isqrt = 1;
+    $isqrt++ while ( $isqrt + 1 )**2 <= $N;
+
+    # Display the result
+    say $isqrt;
+}
+
+main(@ARGV);
diff --git a/challenge-133/sgreen/perl/ch-2.pl b/challenge-133/sgreen/perl/ch-2.pl
new file mode 100755
index 0000000000..8aab074fe3
--- /dev/null
+++ b/challenge-133/sgreen/perl/ch-2.pl
@@ -0,0 +1,53 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+
+use List::Util 'sum';
+
+sub _digit_sum {
+    # Given a string of numbers, calculate the sum of the digits
+    my $string = shift;
+    return sum split //, $string;
+}
+
+sub _prime_factors_sum {
+    my $number  = shift;
+    my %factors = ();
+    my $counter = 2;
+
+    # Get the primes that make up this number
+    while ( $number != 1 ) {
+        if ( $number % $counter == 0 ) {
+            $factors{$counter}++;
+            $number /= $counter;
+        }
+        else {
+            $counter++;
+        }
+    }
+
+    # A prime is not a composite number, and therefore cannot be a
+    #  Smiths number. Returning -1 ensures the eqaulity is false
+    return -1 if scalar( keys(%factors) ) == 1 and ( values(%factors) )[0] == 1;
+
+    # Return the sum of they sum of digits in the prime multiplied by the power
+    # For example 265 = 5¹ * 53¹. The equation is 5 * 1 + (5 + 3) * 1
+    return sum( map { _digit_sum($_) * $factors{$_} } keys %factors );
+}
+
+sub main {
+    my @smiths = ();
+
+    my $number = 1;
+    while ( ++$number ) {
+        # Add to the array if this is a Smiths number
+        push @smiths, $number if _digit_sum($number) == _prime_factors_sum($number);
+        last if @smiths == 10;
+    }
+
+    say join ', ', @smiths;
+}
+
+main();