In this series, I'll share my progress with the 2023 version of Advent of Code.
Check the first post for a short intro to this series.
You can also follow my progress on GitHub.
December 5th
The puzzle of day 5 is absolute horror. A naive implementation of the logic does not work for part 2. So far, I've only solved the first part 😞.
My pitfall for this puzzle: A naive implementation is not going to cut it but I'm struggling with a more elegant and optimized solution. I will update this post as soon as I do of course 😄
UPDATE: In the end a brute-force approach with the naive implementation did work, it took quite some time on my laptop to compute.
Solution here, do not click if you want to solve the puzzle first yourself
#!/usr/bin/env python3 import sys with open('input-small.txt') as infile: lines = infile.readlines() seeds = [int(s) for s in lines[0].strip().split(': ')[1].split(' ')] line_nr = 3 def parse_mapping(lines, line_nr): result = [] while lines[line_nr].strip(): mapping = lines[line_nr].strip().split(' ') start = int(mapping[1]) end = start + int(mapping[2]) shift = int(mapping[0]) - start result.append((start, end, shift)) if line_nr < len(lines) - 1: line_nr += 1 else: break if line_nr < len(lines) - 1: line_nr += 2 return line_nr, result def do_mappings(number, mappings): for mapping in mappings: for m in mapping: if number >= m[0] and number < m[1]: number += m[2] break return number [line_nr, seed_to_soil] = parse_mapping(lines, line_nr) [line_nr, soil_to_fertilizer] = parse_mapping(lines, line_nr) [line_nr, fertilizer_to_water] = parse_mapping(lines, line_nr) [line_nr, water_to_light] = parse_mapping(lines, line_nr) [line_nr, light_to_temperature] = parse_mapping(lines, line_nr) [line_nr, temperature_to_humidity] = parse_mapping(lines, line_nr) [line_nr, humidity_to_location] = parse_mapping(lines, line_nr) lowest_location = None while seeds: start = int(seeds.pop(0)) end = start + int(seeds.pop(0)) for s in range(start, end): location = do_mappings(s, [seed_to_soil, soil_to_fertilizer, fertilizer_to_water, water_to_light, light_to_temperature, temperature_to_humidity, humidity_to_location]) if not lowest_location or location < lowest_location: lowest_location = location print(f'New lowest: {lowest_location}') print(lowest_location)
That's it! See you again tomorrow!
Top comments (0)