65 lines
1.9 KiB
Python
65 lines
1.9 KiB
Python
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from itertools import zip_longest
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def grouper(n, iterable, fillvalue=None):
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"grouper(3, 'ABCDEFG', 'x') --> ABC DEF Gxx"
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args = [iter(iterable)] * n
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return zip_longest(fillvalue=fillvalue, *args)
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def part1(sections):
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# consume seed section
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_, seeds = next(sections)
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seeds = [int(s) for s in seeds]
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print(seeds)
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for name, numbers in sections:
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# item: range_start, len, offset
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#mapping = []
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#for dst, src, length in grouper(3, numbers):
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#mapping.append((src, lenght, dst))
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#src = range(int(src), int(src) + int(length))
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#dst = range(int(dst), int(dst) + int(length))
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#for k, v in zip(src, dst):
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# mapping[k] = v
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# apply current mapping on input (using linear search)
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new_seeds = []
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for seed in seeds:
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for dst, src, length in grouper(3, numbers):
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src, length, dst = int(src), int(length), int(dst)
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end = dst + (length - 1)
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if src <= seed < end:
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new_seed = seed + (dst-src)
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new_seeds.append(new_seed)
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break
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else:
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new_seeds.append(seed)
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seeds = new_seeds
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print(seeds)
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#seeds = [mapping.get(s, None) or s for s in seeds]
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print(f"Part 1, lowest location number = {min(seeds)}")
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def parse_input(infile):
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with open(infile) as f:
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sections = f.read().split("\n\n")
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sections = ((title, numbers) for title, numbers in (s.split(":") for s in sections))
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sections = ((title, numbers.split()) for title, numbers in sections)
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return sections
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if __name__ == "__main__":
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import sys
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import os
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SCRIPTPATH = os.path.dirname(os.path.realpath(__file__))
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infile = next(iter(sys.argv[1:]), None)
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sections = parse_input(infile or os.path.join(SCRIPTPATH, "example.txt"))
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part1(sections)
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