aoc7.py

path = []
dirs = set()
size = {}
lines = [line.strip() for line in open("./aoc7.data")]
while lines:
    line = lines.pop(0)
    if line == "$ cd /": line = "$ cd C:"
    if line == "$ cd ..":
        path.pop()
    elif line.startswith("$ cd "):
        name = line[5:]
        path.append(name)
        dirs.add("/".join(path))
    elif line == "$ ls":
        while lines and not lines[0].startswith("$ "):
            line = lines.pop(0)
            if line.startswith("dir "):
                continue
            else:
                s,n = line.split(" ")
                k = "/".join(path + [n])
                assert k not in size
                size[k] = int(s)
    else:
        assert false

def subdirsize(p):
    return sum(v for k, v in size.items() if k.startswith(p+"/"))

totsize = {}
for d in dirs:
    totsize[d] = subdirsize(d)

totsize1 = {k:v for k, v in totsize.items() if v < 100_000}
print(dirs)
print(size)
print(totsize)
print(totsize1)
print(sum(v for v in totsize1.values()))

total = 70000000
enough = 30000000
used = totsize['C:']

print({k: v for k, v in totsize.items() if total - used + v >= enough})
print(min(v for k, v in totsize.items() if total - used + v >= enough))