52 lines
1.8 KiB
Python
52 lines
1.8 KiB
Python
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# SPDX-License-Identifier: MIT
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# Copyright (c) 2022 Akumatic
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#
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# https://adventofcode.com/2022/day/15
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from re import findall
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def read_file(filename: str = "input.txt") -> list:
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pattern = "Sensor at x=(.+), y=(.+): closest beacon is at x=(.+), y=(.*)"
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with open(f"{__file__.rstrip('code.py')}{filename}", "r") as f:
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return [[int(x) for x in findall(pattern, line)[0]] for line in f.readlines()]
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def combine_ranges(ranges: list) -> list:
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new_ranges = list()
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start, stop = ranges[0]
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for i in range(1, len(ranges)):
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if ranges[i][0] > stop:
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new_ranges.append(range(start, stop))
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start, stop = ranges[i]
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continue
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if ranges[i][1] > stop:
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stop = ranges[i][1]
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new_ranges.append(range(start, stop))
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return new_ranges
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def get_blocked_ranges(coords: list, line: int, _min = float('-inf'), _max = float('inf')) -> list:
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ranges = list()
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for sx, sy, bx, by in coords:
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sb_dist = abs(bx - sx) + abs(by - sy)
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height_dist = abs(sy - line)
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if height_dist > sb_dist:
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continue
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x_min = max(sx - (sb_dist - height_dist), _min)
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x_max = min(sx + (sb_dist - height_dist), _max)
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ranges.append((x_min, x_max))
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return combine_ranges(sorted(ranges))
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def part1(vals: list, test: bool = False) -> int:
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return sum(len(r) for r in get_blocked_ranges(vals, 10 if test else 2000000))
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def part2(vals: list, test: bool = False) -> int:
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max_val = 20 if test else 4000000
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for i in range(max_val + 1):
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ranges = get_blocked_ranges(vals, i, 0, max_val)
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if len(ranges) > 1:
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return (ranges[0].stop + 1) * 4000000 + i
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if __name__ == "__main__":
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vals = read_file()
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print(f"Part 1: {part1(vals)}")
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print(f"Part 2: {part2(vals)}")
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