21 lines
524 B
Python
21 lines
524 B
Python
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def getStartingNumbers(filename):
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with open(filename, "r") as f:
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return [int(n) for n in f.read().split(",")]
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numbers = getStartingNumbers("input.txt")
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occurences = {n: [i] for i,n in enumerate(numbers)}
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while len(numbers) < 2020:
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lastNumber = numbers[-1]
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if len(occurences[lastNumber]) > 1:
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number = occurences[lastNumber][-1] - occurences[lastNumber][-2]
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else:
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number = 0
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occurences[number] = occurences.get(number, [])
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occurences[number].append(len(numbers))
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numbers.append(number)
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print(numbers[2019]) |