aoc2024/d11/run.py

import sys
from math import log10

D = dict()  # cache

def mutate(n:int, t:int) -> int:
  x = D.get((n,t),-1)
  if x < 0:
    if t == 0:
       x = 1
    elif n == 0:
      x = mutate(1, t-1)
    elif (digits := int(log10(n))+1) & 1 == 0: # even nb of digits
      l, r = divmod(n, 10**(digits//2))
      x = mutate(l, t-1) + mutate(r, t-1)
    else:
      x = mutate(n*2024, t-1)
    D[(n,t)] = x
  return x

stones = [int(n) for n in sys.stdin.read().strip().split(" ")]

for times in [25,75]:
  print(sum(mutate(stone, times) for stone in stones))