add solution for left rotation task from c-078

1 files changed, 32 insertions, 0 deletions

diff --git a/challenge-078/alexander-pankoff/perl/ch-2.pl b/challenge-078/alexander-pankoff/perl/ch-2.pl
new file mode 100644
index 0000000000..f4dd950b48
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+++ b/challenge-078/alexander-pankoff/perl/ch-2.pl
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+#!/usr/bin/env perl
+use v5.20;
+use utf8;
+use strict;
+use warnings;
+use autodie;
+use feature qw(say signatures);
+no warnings 'experimental::signatures';
+
+#  You are given array @A containing positive numbers and @B containing one or
+#  more indices from the array @A.
+#
+#  Write a script to left rotate @A so that the number at the first index of @B
+#  becomes the first element in the array. Similary, left rotate @A again so
+#  that the number at the second index of @B becomes the first element in the
+#  array.
+
+my @A = ( 10, 20, 30, 40, 50 );
+my @B = ( 3, 4 );
+
+for my $index (@B) {
+    say '[' . join( ', ', left_rotate( $index, @A ) ) . ']';
+}
+
+sub left_rotate ( $index, @array ) {
+    while ( $index-- ) {
+        my $top = shift @array;
+        push @array, $top;
+    }
+
+    return @array;
+}