Week 247 Task 2

1 files changed, 20 insertions, 0 deletions

diff --git a/challenge-247/cheok-yin-fung/perl/ch-2.pl b/challenge-247/cheok-yin-fung/perl/ch-2.pl
new file mode 100644
index 0000000000..672f922235
--- /dev/null
+++ b/challenge-247/cheok-yin-fung/perl/ch-2.pl
@@ -0,0 +1,20 @@
+use v5.30.0;
+use warnings;
+use List::Util qw/max/;
+use List::MoreUtils qw/slide/;
+
+sub ch {
+    my $str = $_[0];
+    my @arr = split "", $str;
+    my @pairs = slide {$a.$b} @arr;
+    my %freq;
+    $freq{$_}++ for @pairs;
+    my $mx = max values %freq;
+    my @ps = sort {$a cmp $b} grep {$freq{$_} == $mx} keys %freq;
+    return $ps[0]; 
+}
+
+
+use Test::More tests=>2;
+ok ch("abcdbca") eq "bc";
+ok ch("cdeabeabfcdfabgcd") eq "ab";