Advent of Code - Day 12 Part 1 : 3h56:00 (rank 10562) Part 2 : 10h46:51 (rank 8638) So far, this was the hardest day, by a mile. I spent a long time in solving this problem, but I finally ended with a clear and concise code (about 80 lines). Like most of the participants who solved the problem, I used a recursive search function with memoization. The code (in Scala) runs in about 600 ms for both parts combined. I submitted a wrong answer again at my first attempt for Part 1. #AdventOfCode