p7.noul

day := 7;
import "advent-prelude.noul";

puzzle_input := advent_input();

# We assume every directory is ls'd exactly once, which just means we can
# ignore ls commands and, whenever we see a file, put it in the directory we
# most recently cd'd to.
pwd := [];
csize := {:0};
for (line <- puzzle_input.lines) (
	switch (line.words)
	case "$", "cd", "/" -> (pwd = [])
	case "$", "cd", ".." -> pop pwd
	case "$", "cd", x -> (pwd append= x)
	case "$", "ls" -> null
	case "dir", _ -> null
	case size, _name -> (
		for (p <- prefixes(pwd)) csize[p] += int(size)
	)
);

submit! 1, csize.values filter (<= 100000) then sum;

# I was too paranoid that the number starting 7 would have more 0s than the
# number starting 3 so I copied these constants in. Definitely nothing to do
# with all mental arithmetic faculties shutting down under time pressure
needed := 70000000 - 30000000;
cur := csize[[]];

submit! 2, csize.values filter (>= (cur - needed)) then min