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from collections import Counter
from itertools import pairwise
from utils import open_day
PairCounts = Counter[tuple[str, str]]
with open_day(14) as f:
chunks = f.read().rstrip().split('\n\n')
template = chunks[0]
rules = { (p[0][0], p[0][1]): p[1] for p in (l.split(' -> ') for l in chunks[1].split('\n')) }
def step(pairs: PairCounts, rules: list[str, str]) -> PairCounts:
newcount: PairCounts = Counter()
for pair, count in pairs.items():
insert = rules[pair]
newcount[(pair[0], insert)] += count
newcount[(insert, pair[1])] += count
return newcount
def solution(pairs: PairCounts, template: str) -> int:
c = Counter()
for pair, count in pairs.items():
c[pair[0]] += count
c[template[-1]] += 1
common = c.most_common()
return common[0][1] - common[-1][1]
pairs = Counter(pairwise(template))
for _ in range(10): pairs = step(pairs, rules)
print(solution(pairs, template))
for _ in range(30): pairs = step(pairs, rules)
print(solution(pairs, template))
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