33 lines
888 B
Python
33 lines
888 B
Python
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# SPDX-License-Identifier: MIT
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# Copyright (c) 2020 Akumatic
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#
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#https://adventofcode.com/2020/day/10
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def readFile() -> list:
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with open(f"{__file__.rstrip('code.py')}input.txt", "r") as f:
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return [int(line) for line in f.read().strip().split("\n")]
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def part1(input: list) -> int:
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count = [0, 0, 1]
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cur = 0
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for num in input:
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count[num - cur - 1] += 1
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cur = num
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return count[0] * count[2]
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def count_ways(input, cur, cache):
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if cur in cache:
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return cache[cur]
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cache[cur] = sum([count_ways(input, i, cache) for i in range(cur + 1, cur + 4) if i in input])
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return cache[cur]
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def part2(input: list) -> int:
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cache = {input[-1]: 1}
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count_ways(input, 0, cache)
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return cache[0]
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if __name__ == "__main__":
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input = readFile()
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input.sort()
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print(f"Part 1: {part1(input)}")
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print(f"Part 2: {part2(input)}")
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