euler/python/e057.py

from lib_misc import gcd
from lib_misc import get_digit_count


def add_fractions(n1, d1, n2, d2):
    d = d1 * d2
    n1 = n1 * (d // d1)
    n2 = n2 * (d // d2)
    n = n1 + n2
    p = gcd(n, d)
    return (n // p, d // p)


def next_expension(n, d):
    n, d = add_fractions(1, 1, n, d)
    return add_fractions(1, 1, d, n)


def euler_057():
    c = 0
    n, d = (3, 2)
    for i in range(1000):
        if get_digit_count(n) > get_digit_count(d):
            c += 1
        n, d = next_expension(n, d)
    return c


if __name__ == "__main__":
    print("e057.py: " + str(euler_057()))
    assert(euler_057() == 153)