70 lines
2.3 KiB
Python
70 lines
2.3 KiB
Python
from collections import defaultdict
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from aocd.models import Puzzle
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from aocd import submit
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def get_sizes_a(dirs: dict, max_size: int) -> int:
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"""
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return the size of all dirs which are at most max_size big
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"""
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filtered_dirs = [ value for value in dirs.values() if value < max_size]
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return sum(filtered_dirs)
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def get_sizes_b(dirs: dict, needed_size: int) -> int:
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"""
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return the smallest size of a dir which when deleted amounts
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to the needed size of 30M.
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"""
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total_size = 70000000
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used_size = dirs[('/',)]
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max_free = needed_size - (total_size - used_size)
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filtered_dirs = [ value for value in dirs.values() if value > max_free]
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return min(filtered_dirs)
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def parse_input(input_str: str) -> list:
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"""
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the input string consists of the following four message types
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- $ cd .. -> pop dir name from stack
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- $ cd [dir] -> push dir name to stack
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- $ ls -> ignore
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- dir [dir] -> ignore
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- [size] [file] -> sum up the sizes of all files in this dir
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parsing is done by implementing a state machine which gathers all
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available information in the following dictionary.
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- {list['/','dir','path']:int(size_sum)}
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"""
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path = []
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dirs = defaultdict(int)
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for line in input_str.splitlines():
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match line.split():
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case ('$', 'cd', '..'):
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path.pop()
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case ('$', 'cd', name):
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path.append(name)
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case ('$', 'ls'):
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continue
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case ('dir', _):
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continue
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case (size, file):
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size = int(size)
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for i in range(len(path)):
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key = tuple(path[:i+1]) # list not hashable
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dirs[key] += size
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return dirs
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if __name__ == "__main__":
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# get puzzle and parse data
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puzzle = Puzzle(year=2022, day=7)
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dirs = parse_input(puzzle.input_data)
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# part a: get the sum of all dirs where the size is at most 100k
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answer_a = get_sizes_a(dirs, 100000)
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print(f"{answer_a}")
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submit(answer_a, part="a", day=7, year=2022)
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# part b: find the smallest D (huehue) that will free up at least 30M
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answer_b = get_sizes_b(dirs, 30000000)
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print(f"{answer_b}")
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submit(answer_b, part="b", day=7, year=2022)
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