33 lines
619 B
Python
33 lines
619 B
Python
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#!/usr/bin/env python
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def read_input():
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with open('input.txt', 'r') as f:
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for line in f:
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yield line.strip()
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def compare(a, b):
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if len(a) != len(b):
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return None
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change = None
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for i in range(len(a)):
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if a[i] != b[i]:
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if change is None:
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change = i
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else:
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return None
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return a[:change]+a[change+1:]
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boxes = []
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result = None
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for box in read_input():
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for b in boxes:
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result = compare(box, b)
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if result:
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break
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if result:
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break
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boxes.append(box)
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print(result)
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