adventofcode2024/day11/sol.py

def solve(file):
    nums = file.read().split()

    for i in range(25):
        if len(nums) < 100:
            print(i, nums)
        new = []
        for n in nums:
            if n == '0':
                new.append('1')
            elif len(n)%2 == 0:
                new.append(n[:len(n)//2])
                new.append(n[len(n)//2:].lstrip('0') or '0')
            else:
                new.append(str(int(n)*2024))
        nums = new
    print(len(nums))

def solve2(file):
    nums = file.read().split()

    print(sum(evolve(n, 25) for n in nums))
    print(sum(evolve(n, 75) for n in nums))

book = {}
def evolve(n, t):
    if t == 0:
        return 1
    elif (n,t) in book:
        return book[n,t]
    else:
        if n == '0':
            x = evolve('1', t-1)
        elif len(n)%2 == 0:
            x = evolve(n[:len(n)//2], t-1)
            x += evolve(n[len(n)//2:].lstrip('0') or '0', t-1)
        else:
            x = evolve(str(int(n)*2024), t-1)
        book[n,t] = x
        return x

from io import StringIO
#solve(StringIO("0 1 10 99 999"))
solve2(StringIO("0 1 10 99 999"))
#solve(open("input"))
solve2(open("input"))