aoc2017-day15-2

from functools import reduce

def generate(current, factor, rem, scale=1):
    while True:
        current = (current * factor) % rem
        if current % scale == 0: yield current

gen = (1 if (x & 0xFFFF) == (y & 0xFFFF) else 0 for x,y in
       zip(generate(618,16807,2**31-1,4),
           generate(814,48271,2**31-1,8)))
s = reduce(lambda x,y: x+y,(next(gen) for _ in range(5000000)))
print(s)