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 8th
The puzzle of day 8 was not so hard. I like graph problems, although this was pretty basic.
My pitfall for this puzzle: I have no clue how to find the number that's a common factor for all path lengths. Something similar to Greatest Common Divisor, but what 🤷. In the end a brute force approach worked and doesn't take that long on my M1 laptop.
Solution here, do not click if you want to solve the puzzle first yourself
#!/usr/bin/env python3 import math with open('input.txt') as infile: lines = infile.readlines() directions = [d for d in lines[0].strip()] graph = {} for line in lines[2:]: parts = line.strip().split(' = ') targets = parts[1][1:-1].split(', ') graph[parts[0]] = {'L': targets[0], 'R': targets[1]} dir_idx = 0 steps = 0 nodes = [n for n in graph.keys() if n.endswith('A')] finished = [] while len([n for n in nodes if not n.endswith('Z')]) > 0: steps += 1 for idx, n in enumerate(nodes): if idx in [f[0] for f in finished]: continue nodes[idx] = graph[n][directions[dir_idx]] if nodes[idx].endswith('Z'): finished.append((idx, steps)) if dir_idx < len(directions) - 1: dir_idx += 1 else: dir_idx = 0 for f in finished: print(f'Finished node {f[0]} in {f[1]} steps') highest = max([f[1] for f in finished]) total = highest while True: all_divisors = True for f in finished: if total % f[1] != 0: all_divisors = False if all_divisors: break else: total += highest print(total)
That's it! See you again tomorrow!
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