Jake Pullen
87 lines
2.3 KiB
Python
87 lines
2.3 KiB
Python
testing = 0
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if not testing:
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with open(r"2024/05\input.txt", "r") as file:
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input = file.read()
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else:
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input = """47|53
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97|13
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97|61
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97|47
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75|29
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61|13
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75|53
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29|13
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97|29
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53|29
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61|53
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97|53
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61|29
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47|13
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75|47
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97|75
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47|61
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75|61
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47|29
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75|13
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53|13
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75,47,61,53,29
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97,61,53,29,13
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75,29,13
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75,97,47,61,53
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61,13,29
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97,13,75,29,47"""
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# first we split the input into the two parts
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# the first part is the "rules" and the second part is the "updates"
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rules, updates = input.split("\n\n")
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# print(rules)
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# print('^v^v^v^')
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# print(updates)
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# for each rule the left side is the page that must come before the right side
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# to check the updates are correct we need to check that the left side of the update is before the right side
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# if all updatesare correct then the rules are correct and we need to store the 'middle' number
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# lets assign each update to a list of numbers
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update_lists = []
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for update in updates.split("\n"):
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update_lists.append(list(map(int, update.split(","))))
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#print(update_lists)
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# lets also assign the rules to a list of tuples of numbers
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rule_tuples = []
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for rule in rules.split("\n"):
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rule_tuples.append(tuple(map(int, rule.split("|"))))
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#print(rule_tuples)
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valid_updates = []
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# now for each update we need to check that it follows the rules
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for update in update_lists:
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valid = True
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# we need to check that the update is ordered correctly based on the rules
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for rule in rule_tuples:
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# if the update does not contain the any number in the rules we can ignore that rule
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if rule[0] not in update or rule[1] not in update:
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continue
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# if the left side is before the right side then we can break out of the loop
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if update.index(rule[0]) < update.index(rule[1]):
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continue
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# if the right side is before the left side then we can break out of the loop
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if update.index(rule[0]) > update.index(rule[1]):
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valid = False
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break
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if valid:
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valid_updates.append(update)
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print('The valid updates are',valid_updates)
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numbers_to_sum = []
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for update in valid_updates:
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update_len = len(update)
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# we need to find the middle number
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middle = update_len // 2
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numbers_to_sum.append(update[middle])
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print('The numbers to sum are',numbers_to_sum)
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print('The sum of the numbers is',sum(numbers_to_sum))
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