My Advent of Code solutions in Python.
kevinyap.ca/2019/12/going-fast-in-advent-of-code/
advent-of-code
python
Add 2022/07
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+68
2022/day07.py
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2022/day07.py
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import fileinput
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class File:
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def __init__(self, name, size=0):
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self.name = name
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self.size = size
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self.children = []
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self.parent = None
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FS = File('/')
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pwd = FS
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for line in fileinput.input():
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if line.startswith('$'):
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parts = line.split()
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cmd = parts[1]
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if cmd == 'cd':
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directory = parts[2]
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if directory == '..':
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pwd = pwd.parent
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else: # cd-ing into a new directory
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file = File(directory)
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file.parent = pwd
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pwd.children.append(file)
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pwd = file
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# The current line is telling us something about
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# either a file and its size, or a new directory.
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else:
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size, name = line.split()
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# Only care if we are looking at a file.
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if size != 'dir':
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file = File(name, int(size))
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pwd.children.append(file)
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SIZES = {}
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def dir_size(file):
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"""Return the size of the given file."""
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if not file.children:
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return file.size
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total_size = 0
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for child in file.children:
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total_size += dir_size(child)
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SIZES[file] = total_size
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return total_size
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# Perform DFS to seed `SIZES`.
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USED = dir_size(FS)
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# Part 1
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print("Part 1:", sum(s for s in SIZES.values() if s < 100000))
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# Part 2
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AVAILABLE = 70000000
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NEED = 30000000
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UNUSED = AVAILABLE - USED
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for size in sorted(SIZES.values()):
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if UNUSED + size >= NEED:
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print("Part 2:", size)
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break
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