67 lines
1.5 KiB
Python
67 lines
1.5 KiB
Python
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input = open("input", 'r').read().strip()
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# d = [int(line) for line in input]
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d = {id: int(line) for id, line in enumerate(input)}
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def entry(pos, id, length):
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return {"pos": pos, "id": id, "length": length}
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pos = 0
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s = []
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e = []
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for id, leng in d.items():
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if leng <= 0:
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continue
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if id % 2 == 0:
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s.append(entry(pos, id // 2, leng))
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else:
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e.append(entry(pos, -1, leng))
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pos += leng
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# print(d)
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def run():
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start = 0
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end = len(d) - 1
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if end % 2 != 0:
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end -= 1
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pos = 0
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checksum = 0
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while start <= end:
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if start % 2 == 0: # Full
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checksum += pos * (start // 2)
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pos += 1
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d[start] -= 1
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while d[start] == 0:
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start += 1
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else: # Empty
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checksum += pos * (end // 2)
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pos += 1
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d[start] -= 1
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while d[start] == 0:
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start += 1
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d[end] -= 1
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while d[end] == 0:
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end -= 2
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return checksum
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def run2():
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# a = s[-1]
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# print(a)
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for file in reversed(s):
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for empty in e:
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if empty['length'] >= file['length'] and file['pos'] > empty['pos']:
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file['pos'] = empty['pos']
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empty['pos'] += file['length']
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empty['length'] = empty['length'] - file['length']
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break
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checksum = sum([
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sum([(file['pos']+i) * file['id'] for i in range(file['length'])]) for file in s
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])
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return checksum
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print(run())
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print(run2())
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