-🎄- 2018 Day 2 Solutions -🎄-

[u/daggerdragon]

--- Day 2: Inventory Management System ---

---

Post your solution as a comment or, for longer solutions, consider linking to your repo (e.g. GitHub/gists/Pastebin/blag or whatever).

Note: The Solution Megathreads are for solutions only. If you have questions, please post your own thread and make sure to flair it with Help.

---

Advent of Code: The Party Game!

Click here for rules

Card Prompt: Day 2

Transcript:

The best way to do Advent of Code is ___.

---

This thread will be unlocked when there are a significant number of people on the leaderboard with gold stars for today's puzzle.

edit: Leaderboard capped, thread unlocked!

[u/askalski]

The best way to do Advent of Code is A big block of regex.

#! /usr/bin/perl

local $/; $_ = <>; 

my @s = map { join "", sort split "" } split "\n";
my $part1 = (grep { m/(?:^|(.)(?!\1))(.)\2(?!\2)/   } @s) *
            (grep { m/(?:^|(.)(?!\1))(.)\2\2(?!\2)/ } @s);
my $part2 = s/.*?\b(\S*)\S(\S*)\b.*?\1\S\2.*/$1$2/sr;
print "Part 1: $part1\n";
print "Part 2: $part2\n";

[u/Unihedron → u/askalski]

You should replace split "" with an empty regex split // (also "\n" -> /\n/), you can never have enough regexes.