28 lines
627 B
Python
28 lines
627 B
Python
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def counts(nums: list[int]) -> dict[int, int]:
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ret = {}
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for n in nums:
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if n in ret:
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ret[n] += 1
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else:
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ret[n] = 1
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return ret
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if __name__ == '__main__':
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with open('1.input') as file:
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left, right = [], []
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for line in file:
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l, r = line.split()
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l, r = int(l), int(r)
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left.append(l)
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right.append(r)
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# how many times does each number apear in each list
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right = counts(right)
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score = 0
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for n in left:
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if n not in right: continue
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score += n * right[n]
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print(score)
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