37 lines
1.2 KiB
Python
37 lines
1.2 KiB
Python
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import time
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def solve(blocks):
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new_bridges = [[block] for block in blocks if 0 in block]
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strongest = 0
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longest_strength = 0
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while new_bridges:
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bridges = new_bridges
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new_bridges = []
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for bridge in bridges:
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new_bridges.extend(list(extend(bridge, blocks)))
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if new_bridges:
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longest_strength = max(bridge_strength(bridge) for bridge in new_bridges)
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strongest = max(strongest, longest_strength)
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return strongest, longest_strength
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def bridge_strength(bridge):
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return sum(map(sum, bridge))
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def extend(bridge, blocks):
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unused = list(filter(lambda b: b not in bridge and b[::-1] not in bridge, blocks))
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for block in unused:
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if bridge[-1][1] == block[0]:
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yield bridge + [block]
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elif bridge[-1][1] == block[1]:
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yield bridge + [block[::-1]]
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if __name__ == '__main__':
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start = time.time()
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block_list = []
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with open('input') as f:
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for line in f:
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block_list.append(tuple(map(int, line.split('/'))))
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block_list = [(a, b) if a < b else (b, a) for a, b in block_list]
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print('Part 1: {}\nPart 2: {}'.format(*solve(block_list)))
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print(f'Solved in {time.time() - start}')
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