Add blog post by E. Choroba about 051 (3Sum and Colourful Numbers)

Also, simplify the solution of the second task: we don't need to pad
the array.

2 files changed, 2 insertions, 3 deletions

diff --git a/challenge-051/e-choroba/blog.txt b/challenge-051/e-choroba/blog.txt
new file mode 100644
index 0000000000..66ce5ed9d2
--- /dev/null
+++ b/challenge-051/e-choroba/blog.txt
@@ -0,0 +1 @@
+http://blogs.perl.org/users/e_choroba/2020/03/perl-weekly-challenge-051-3-sum-and-colourful-numbers.html
diff --git a/challenge-051/e-choroba/perl/ch-2.pl b/challenge-051/e-choroba/perl/ch-2.pl
index 47505bbab9..b911cb2012 100755
--- a/challenge-051/e-choroba/perl/ch-2.pl
+++ b/challenge-051/e-choroba/perl/ch-2.pl
@@ -12,9 +12,7 @@ sub is_colorful_number {
     my $count = 0;
     for my $length (1 .. $max_length) {
         for my $pos (0 .. $max_length - $length) {
-            my @pattern = (
-                (0) x $pos, (1) x $length, (0) x ($max_length - $pos - $length)
-            );
+            my @pattern = ((0) x $pos, (1) x $length);
             undef $uniq{
                 product((split //, $n)[ grep $pattern[$_], 0 .. $#pattern ])
             };