Merge pull request #2327 from shawnw/challenge-078-solution

Challenge 078, both parts in perl

2 files changed, 59 insertions, 0 deletions

diff --git a/challenge-078/shawn-wagner/perl/ch1.pl b/challenge-078/shawn-wagner/perl/ch1.pl
new file mode 100755
index 0000000000..9fda9a2515
--- /dev/null
+++ b/challenge-078/shawn-wagner/perl/ch1.pl
@@ -0,0 +1,29 @@
+#!/usr/bin/env perl
+use warnings;
+use strict;
+use feature qw/say/;
+use List::Util qw/max/;
+use POSIX qw/INT_MIN/;
+
+sub leaders {
+  my @A = @_;
+  my $rmax = INT_MIN;
+  my @maxes = ($rmax);
+  for my $i (reverse 0..$#A) {
+    $rmax = max $rmax, $A[$i];
+    unshift @maxes, $rmax;
+  }
+  my @leaders;
+  for my $i (0 .. $#A) {
+    push @leaders, $A[$i] if $A[$i] > $maxes[$i+1];
+  }
+  if (@leaders) {
+    local $, = ", ";
+    say "(@leaders)";
+  } else {
+    say "(0)";
+  }
+}
+
+leaders 9, 10, 7, 5, 6, 1;
+leaders 3, 4, 5;
diff --git a/challenge-078/shawn-wagner/perl/ch2.pl b/challenge-078/shawn-wagner/perl/ch2.pl
new file mode 100755
index 0000000000..af19c53165
--- /dev/null
+++ b/challenge-078/shawn-wagner/perl/ch2.pl
@@ -0,0 +1,30 @@
+#!/usr/bin/env perl
+use warnings;
+use strict;
+use feature qw/say/;
+
+sub rotate_left :prototype(\@$) {
+  my ($A, $idx) = @_;
+  my @A = @$A;
+  my @left = splice @A, 0, $idx;
+  push @A, @left;
+  return \@A;
+}
+
+sub rotate_left_multi :prototype(\@\@) {
+  my ($A, $B) = @_;
+  for my $idx (@$B) {
+    my $rotated = rotate_left @$A, $idx;
+    say "[@$rotated]";
+  }
+  say "---";
+}
+
+
+my @A = (10, 20, 30, 40, 50);
+my @B = (3, 4);
+rotate_left_multi @A, @B;
+
+@A = (7, 4, 2, 6, 3);
+@B = (1, 3, 4);
+rotate_left_multi @A, @B;