48 lines
1.3 KiB
Python
48 lines
1.3 KiB
Python
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input = open("input", 'r')
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cardinal_offset = [x+y for x in [-1,0,1] for y in [-1j,0,1j] if x+y != 0]
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papermap = set()
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for x, line in enumerate(input):
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for y, item in enumerate(line.rstrip()):
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if item == "@":
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papermap.add(complex(x,y))
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def part1(pmap, adjacent_min=4):
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accessible = set()
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for location in pmap:
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adjacents = 0
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for offset in cardinal_offset:
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adjacents += 1 if location+offset in pmap else 0
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if adjacents < adjacent_min:
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accessible.add(location)
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print(len(accessible))
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def part2(pmap, adjacent_min=4):
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amap = {}
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to_remove = set()
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# Build adjacency map
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for location in pmap:
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adjacents = 0
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for offset in cardinal_offset:
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adjacents += 1 if location+offset in pmap else 0
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amap[location] = adjacents
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if adjacents < adjacent_min:
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to_remove.add(location)
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starting_value = len(amap)
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while to_remove:
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rm_location = to_remove.pop()
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del amap[rm_location]
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for offset in cardinal_offset:
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if rm_location+offset in amap:
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amap[rm_location+offset] -= 1
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if amap[rm_location+offset] < adjacent_min:
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to_remove.add(rm_location+offset)
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print(starting_value-len(amap))
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part1(papermap)
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part2(papermap)
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