Advent of Code 2023 Day 2

Author

Nathan Moore

— Day 2: Cube Conundrum —

An elf is playing a game of “take the cubes out of the bag”. They contain 12 red, 13 green, and 14 blue cubes. Which of the games are possible from your puzzle input?

What is the sum of the IDs of those games?

with open('data-2023-02.txt', 'r') as f:
    inp = f.read().splitlines()

Create a nice dict / list structure for easy iteration. I’m not sure what part two will be so let us set ourselves up for success. Overall it’s a dictionary with the game number as keys, then lists of dictionaries for each draw for each game.

import re

# here's another python cell for good luck
games = {i.split(':')[0]: i.split(':')[1].split(';') for i in inp}

# check the structure
# games['Game 1']

# create dict to build on
game_dict = dict()

# loop through the dictionary
for k,v in games.items():
    # get the key for the game as number
    z = re.findall(r'\d+', k)[0]
    # an empty list for the dict
    game_dict[z] = []
    # loop through the values in the original list
    for d in v: 
        # print(d)
        # turn each of these into a dictionary
        game_dict[z].append( 
            {re.findall(r'[a-z]+', y)[0]: int(re.findall(r'\d+', y)[0])
            for y in d.split(',')}
            )

game_dict['1']

[{'blue': 7, 'red': 9, 'green': 1},
 {'green': 8},
 {'green': 10, 'blue': 5, 'red': 3},
 {'blue': 11, 'red': 5, 'green': 1}]

Okay, now that the building of the hopefully nice structure is done after much too long, let’s look for good games.

# 12 red cubes, 13 green cubes, and 14 blue cubes
lims = {'red': 12, 'green': 13, 'blue': 14}
counter = 0

# loop through the games
for k,v in game_dict.items():
    found = False
    # loop through the dicts
    for d in v: 
        # print(d)
        # loop through the elements in the dict
        for g,h in d.items(): 
            # if we are in an impossible game
            if h > lims[g]: 
                # print(d)
                # print(k)
                counter += int(k)
                found = True
                break
    # the first break gets out of the d.items() loop, this gets us out of v
        if found == True:
            break

# turns out I'm counting impossible games and we want possible games   
# using ramanujan to get the total of 100 games = (n+1)*(n/2)
101*50-counter

Part one: 2551

— Part Two —

For each game, find the minimum set of cubes that must have been present. What is the sum of the power of these sets?

# create a nice dict to hold the minimum numbers
min_dice = {str(x): {'red': 0, 'green': 0, 'blue': 0} for x in range(1, 101)}

# loop through the games
for k,v in game_dict.items():
    # loop through the dicts
    for d in v: 
        # print(d)
        # loop through the elements in the dict
        for g,h in d.items(): 
            # print(g)
            if h > min_dice[k][g]:
                min_dice[k][g] = h
    # print(min_dice[k])

sum([n['red'] * n['green'] * n['blue'] for m,n in min_dice.items()])

Part two: 62811