sgreen solutions to challenge 138

4 files changed, 76 insertions, 2 deletions

diff --git a/challenge-138/sgreen/README.md b/challenge-138/sgreen/README.md
index 413edf3cdd..9d6781fb66 100644
--- a/challenge-138/sgreen/README.md
+++ b/challenge-138/sgreen/README.md
@@ -1,3 +1,3 @@
-# The Weekly Challenge 137
+# The Weekly Challenge 138
 
-Solution by Simon Green. [Blog](https://dev.to/simongreennet/weekly-challenge-137-3jon)
+Solution by Simon Green. [Blog](https://dev.to/simongreennet/weekly-challenge-138-dh1)
diff --git a/challenge-138/sgreen/blog.txt b/challenge-138/sgreen/blog.txt
new file mode 100644
index 0000000000..2c44b95f2a
--- /dev/null
+++ b/challenge-138/sgreen/blog.txt
@@ -0,0 +1 @@
+https://dev.to/simongreennet/weekly-challenge-138-dh1
diff --git a/challenge-138/sgreen/perl/ch-1.pl b/challenge-138/sgreen/perl/ch-1.pl
new file mode 100755
index 0000000000..3eaf027be6
--- /dev/null
+++ b/challenge-138/sgreen/perl/ch-1.pl
@@ -0,0 +1,30 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+use feature 'say';
+
+use Date::Calc ( 'Day_of_Week', 'leap_year' );
+
+sub main {
+    my $year = shift;
+
+    # Sanity check
+    die "You must specify the year"       unless defined $year;
+    die "Year must be four digits > 1752" unless $year =~ /^[0-9]{4}$/ and $year > 1752;
+
+    # Get the day of week of January 1st, and leap year flag
+    my $day_of_week = Day_of_Week( $year, 1, 1 );    # 1 - Monday, 7 - Sunday
+    my $leap        = leap_year($year);
+
+    # If the 1st of January is Saturday or Sunday, then the Dec 31st (or
+    # Dec 30th in a leap year) isn't a work day.
+    my $workdays = ( $day_of_week != 6 and $day_of_week != 7 ) ? 261 : 260;
+
+    # In a leap year, the Dec 31st is two days later than Jan 1st.
+    ++$workdays if $leap and $day_of_week != 5 and $day_of_week != 6;
+
+    say $workdays;
+}
+
+main(@ARGV);
diff --git a/challenge-138/sgreen/perl/ch-2.pl b/challenge-138/sgreen/perl/ch-2.pl
new file mode 100755
index 0000000000..5a134362ac
--- /dev/null
+++ b/challenge-138/sgreen/perl/ch-2.pl
@@ -0,0 +1,43 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+use feature 'say';
+
+use List::Util 'sum';
+
+sub _can_split {
+    my ( $target, $used, $pool ) = @_;
+
+    # The first number cannot be all digits
+    my $max = $#$used == -1 ? length($pool) - 1 : length($pool);
+
+    foreach my $l ( 1 .. $max ) {
+        if ( $l == length($pool) ) {
+            return 1 if sum( @$used, $pool ) == $target;
+        }
+        else {
+            # We can split the number
+            my $found = _can_split( $target, [ @$used, substr( $pool, 0, $l ) ], substr( $pool, $l ) );
+            return 1 if $found;
+        }
+    }
+
+    return 0;
+}
+
+sub main {
+    my $n = shift;
+
+    # Sanity check
+    die "You must specify a number\n"            unless defined $n;
+    die "The input doesn't look like a number\n" unless $n =~ /^[1-9][0-9]*$/;
+
+    # Check the number is a perfect square
+    my $s = sqrt($n);
+    die "The number isn't a perfect sqaure\n" unless $s == int($s);
+
+    say _can_split( $s, [], $n );
+}
+
+main(@ARGV);