Advent of Code - adventofcode.com

A lot of stacks the past few days...

https://gist.github.com/wence-/500e1bc4633192ac6fee67433aedd974#file-day09-py and so on.

@frankenbike FWIW, your recursive implementation of DFS is not overly idiomatic in imperative languages, the usual approach is:

stack = [start]
seen = set()
while stack:
    n = stack.pop()
    for c in neighbours(n):
        if c not in seen:
            stack.append(c)
            # do whatever...