Anders Englöf Ytterström
0eb961d31c
First part was solved using a list to store stones, since I misinterpreted this paragraph: > No matter how the stones change, their order is > preserved, and they stay on their perfectly > straight line. But since the puzzle question do not require the stones in the correct order, a list (or an OrderedDict) is not required. The pt 1 solution code got killed for eating all RAM, so valuable minutes was lost trying to create a generator instead. It failed. When searching for clues, I ran across multiple people instead utilizing dicts to count occourences. "but what of the order?", I asked, and realized only the counts was relevant.
38 lines
1,000 B
Python
38 lines
1,000 B
Python
from collections import defaultdict
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from output import ints
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def solve(data):
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state = defaultdict(int)
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for e in ints(data):
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state[e] += 1
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for lap in range(75):
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if lap == 25:
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stones_count_25 = sum(state.values())
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queue = list(map(lambda x: x, state.items()))
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for e, delta in queue:
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if e == 0:
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state[1] += delta
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state[0] -= delta
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elif len(str(e)) % 2 == 0:
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i = len(str(e)) // 2
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l, r = int(str(e)[:i]), int(str(e)[i:])
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state[l] += delta
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state[r] += delta
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state[e] -= delta
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else:
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state[e * 2024] += delta
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state[e] -= delta
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stones_count_75 = sum(state.values())
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return stones_count_25, stones_count_75
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if __name__ == "__main__":
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with open("./input/11.txt", "r") as f:
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inp = f.read().strip()
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p1, p2 = solve(inp)
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print(p1)
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print(p2)
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