53 lines
1.5 KiB
Python
53 lines
1.5 KiB
Python
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import aocd
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import math
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import collections
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import itertools
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def solve(data):
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grid = collections.defaultdict(list)
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antinodes = set()
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rows = data.split('\n')
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width = len(rows[0])
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height = len(rows)
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for y, row in enumerate(rows):
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for x, cell in enumerate(row):
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if cell == '.':
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continue
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for prev_x, prev_y in grid[cell]:
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dx = x - prev_x
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dy = y - prev_y
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angle = math.gcd(dx, dy)
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dx, dy = dx // angle, dy // angle
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# In the direction of the previous antenna...
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for i in itertools.count(step=-1):
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if 0 <= (new_x := prev_x + dx*i) < width and 0 <= (new_y := prev_y + dy*i) < height:
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antinodes.add((new_x, new_y))
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else:
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break
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# In the direction of the current antenna...
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for i in itertools.count(step=1):
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if 0 <= (new_x := x + dx*i) < width and 0 <= (new_y := y + dy*i) < height:
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antinodes.add((new_x, new_y))
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else:
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break
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grid[cell].append((x, y))
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return sum(1 for _ in antinodes)
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if __name__ == '__main__':
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puz = aocd.models.Puzzle(year=2024, day=8)
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# data = puz.examples[0].input_data
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data = puz.input_data
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solution = solve(data)
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print(solution)
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aocd.submit(solution, year=2024, day=8, part='b')
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