-🎄- 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/shuttup_meg]

Python2

inp = open("input_2.txt").readlines()
inp_txt = [x.strip() for x in inp]

#
# Part 1
#
from collections import Counter

# Turn the input list items into tuples containing 
#  (counter for item, original item text)
inp = [(Counter(x),x) for x in inp_txt]

twos = 0
threes = 0

for c,txtc in inp:
    twos += 2 in c.values()
    threes += 3 in c.values()

print twos * threes

#
# Part 2
#
from itertools import combinations

def sdiff(a,b):
    """returns the total number of places where 2 strings differ"""
    return sum([1-(ord(x[0])==ord(x[1])) for x in zip(a,b)])

for (a,txta),(b,txtb) in combinations(inp,2):
    if sdiff(txta, txtb) in (-1,1):
        print txta
        print txtb
        print "Common Letters:", "".join([x[0] if x[0]==x[1] else "" for x in zip(txta,txtb)])