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https://github.com/Threnklyn/advent-of-code-go.git
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alexchao26
59 lines
1.6 KiB
Python
59 lines
1.6 KiB
Python
from collections import defaultdict
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def day22(input: str, part: int) -> int:
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total: int = 0
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last_four_diffs_to_price: dict[tuple[int, int, int, int], int] = defaultdict(int)
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for line in input.splitlines():
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nums: list[int] = [int(line)]
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diffs: list[int] = []
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seen_last_fours: set[tuple[int, int, int, int]] = set()
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for _ in range(2000):
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nums.append(get_next_secret_number(nums[-1]))
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diff = nums[-1] % 10 - nums[-2] % 10
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diffs.append(diff)
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total += nums[-1]
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for i in range(3, len(diffs)):
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last_four_diffs = (diffs[i - 3], diffs[i - 2], diffs[i - 1], diffs[i])
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# only count the first time we've seen this set of diffs, aka only sell once
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if last_four_diffs in seen_last_fours:
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continue
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seen_last_fours.add(last_four_diffs)
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last_four_diffs_to_price[last_four_diffs] += nums[i + 1] % 10
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if part == 1:
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return total
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most_bananas = max(last_four_diffs_to_price.values())
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return most_bananas
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def get_next_secret_number(num: int) -> int:
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num = (num ^ (num * 64)) % 16777216
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num = (num ^ (num // 32)) % 16777216
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num = (num ^ (num * 2048)) % 16777216
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return num
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example = """1
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10
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100
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2024"""
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input = open("input.txt").read().strip()
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print(f"part1 example: {day22(example, 1)} want 37327623")
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print(f"part1 actual: {day22(input, 1)} want 17612566393")
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example_part_2 = """1
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2
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3
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2024"""
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print(f"part2 example: {day22(example_part_2, 2)} want 23")
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print(f"part2 actual: {day22(input, 2)} want 1968")
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