7.md

Day 7

	Part 1	Part 2	Total
Time	38:28	4:30	42:58

Part 1

Oh. My. Goodness. I had it in 10 minutes! The structure of this code was entirely unchanged since 10 minutes in. However, instead of storing the path in the dictionary, I stored only the bottom-most folder. This of course did NOT work when there were multiple folders of the same name. I spent the next 20+ minutes trying to figure out why the numbers didn't work until I looked in the input and saw $ cd ngmqbc shortly followed by another $ cd ngmqbc, then it clicked. Very frustrating error, but a whole lot of fun and clever problem!

from helpers.datagetter import data_in, submit
from collections import defaultdict

din = data_in(split=True, numbers=False)
ans = 0

dirs = defaultdict(int)
current = []

for line in din:
    if line.startswith("$ cd"):
        dir = line.split(" ")[2]

        if dir == "..":
            current.pop()
        elif dir == "/":
            current = ["/"]
        else:
            current.append(dir)

    elif line.split(" ")[0].isnumeric():
        for i in range(len(current)):
            path = "/".join(current[0:i+1])
            dirs[path] += int(line.split(" ")[0])

for thing in dirs.values():
### SECTION TO CHANGE FOR PART 2
    if thing <= 100000:
        ans += thing
### END SECTION

print(ans)
submit(ans)

Part 2

Very small modification to look for the smallest folder that can be subtracted to give a used size of less than 40,000,000.

    if dirs["/"] - thing <= 40000000:
        ans = min(thing, ans)