Moved 2021 to a subdir

[aoc.git] / 2021 / 02.pl

diff --git a/2021/02.pl b/2021/02.pl
new file mode 100755 (executable)
index 0000000..b9fbfb5
--- /dev/null
+++ b/2021/02.pl
@@ -0,0 +1,15 @@
+#!/usr/bin/perl -w
+
+use strict;
+
+chomp (my @a = <>);
+my $prev;
+my $inc;
+
+for my $i (0 .. $#a-2) {
+       my $sum = $a[$i]+$a[$i+1]+$a[$i+2];
+       $inc++ if $prev && $sum > $prev;
+       $prev = $sum;
+}
+
+print "$inc\n";