add solution for leader element task from c-078

1 files changed, 39 insertions, 0 deletions

diff --git a/challenge-078/alexander-pankoff/perl/ch-1.pl b/challenge-078/alexander-pankoff/perl/ch-1.pl
new file mode 100644
index 0000000000..9f4a8f1b5c
--- /dev/null
+++ b/challenge-078/alexander-pankoff/perl/ch-1.pl
@@ -0,0 +1,39 @@
+#!/usr/bin/env perl
+use v5.20;
+use utf8;
+use strict;
+use warnings;
+use autodie;
+use feature qw(say signatures);
+no warnings 'experimental::signatures';
+
+use List::Util qw(all reduce);
+
+# You are given an array @A containing distinct integers.
+#
+# Write a script to find all leader elements in the array @A. Print (0) if none
+# found.
+#
+# >> An element is leader if it is greater than all the elements to its right
+# >> side.
+
+my @A = @ARGV;
+
+my @leaders = find_leader_elements(@A);
+@leaders = (0) unless @leaders;
+
+say '(' . join( ', ', @leaders ) . ')';
+
+exit;
+
+sub find_leader_elements(@list) {
+    my $leaders = reduce {
+        my @leaders = @$a;
+        my $current = $b;
+
+        ( all { $current > $_ } @leaders ) ? [ $current, @leaders ] : $a
+    }
+    [], reverse @list;
+
+    return @{$leaders};
+}