Perl solution for week 97, part 2

2 files changed, 43 insertions, 0 deletions

diff --git a/challenge-097/abigail/README.md b/challenge-097/abigail/README.md
index 0e2295286a..1761fd8622 100644
--- a/challenge-097/abigail/README.md
+++ b/challenge-097/abigail/README.md
@@ -66,5 +66,6 @@ Binary Substrings:
 ~~~~
 
 ### Solutions
+* [Perl](perl/ch-2.pl)
 
 ### Blog
diff --git a/challenge-097/abigail/perl/ch-2.pl b/challenge-097/abigail/perl/ch-2.pl
new file mode 100644
index 0000000000..b0d145069e
--- /dev/null
+++ b/challenge-097/abigail/perl/ch-2.pl
@@ -0,0 +1,42 @@
+#!/opt/perl/bin/perl
+
+use 5.032;
+
+use strict;
+use warnings;
+no  warnings 'syntax';
+
+use experimental 'signatures';
+use experimental 'lexical_subs';
+
+#
+# See ../README.md
+#
+
+#
+# Run as: perl ch-2.pl -s SECTIONS < input-file
+#
+
+use Getopt::Long;
+use List::Util qw [min];
+
+GetOptions 's=i'  =>  \my $sections;
+
+die "-s option required" unless defined $sections && $sections > 0;
+
+#
+# To get the minimum number of flips, for each position take the
+# minimum of the number of 0s and the number of 1s, and sum over
+# all the positions
+#
+
+while (<>) {
+    my $sum = 0;
+    chomp;
+    my @chunks = /.{$sections}/g;
+    for (my $i = 0; $i < length $chunks [0]; $i ++) {
+        my $zeros = grep {substr ($_, $i, 1) eq "0"} @chunks;
+        $sum += min $zeros, @chunks - $zeros;
+    }
+    say $sum;
+}