35 lines
1.0 KiB
Python
35 lines
1.0 KiB
Python
#!/usr/bin/python3
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# Import lists of the alphabet so we can find indxes later.
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from string import ascii_lowercase, ascii_uppercase
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commonItems = []
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backpacks = []
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# Read the whole input file to a list.
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with open('input.txt', 'r') as inputFile:
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backpacks = inputFile.readlines()
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# Group the backpacks up into threes and find the common item in each three.
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currentBackpack = 0
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while(currentBackpack < len(backpacks)):
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currentGroup = []
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while(len(currentGroup) < 3):
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currentGroup.append(backpacks[currentBackpack].strip())
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currentBackpack += 1
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for item in currentGroup[0]:
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if(item in currentGroup[1] and item in currentGroup[2]):
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commonItems.append(item)
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break
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# For all of the common items we found, total up the priorities.
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totalPriority = 0
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for item in commonItems:
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if(item in ascii_lowercase):
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totalPriority += (ascii_lowercase.index(item) + 1)
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elif(item in ascii_uppercase):
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totalPriority += (ascii_uppercase.index(item) + 27)
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# Print the answer.
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print(totalPriority)
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