PE #26

from decimal import *
getcontext().prec = 2000


def find_recurring_length(divisor):
    digits = (Decimal(1) / Decimal(divisor)).as_tuple().digits[:-1]
    precision = getcontext().prec -1
    if len(digits) != precision:
        return 0
    recurring = 0
    for i in range(0, 7):
        l_digits = digits[i:]
        l = len(l_digits)
        for j in range(1, int(l / 2)):
            multiplier = int(l/j)
            if l_digits[:j] * (multiplier) == l_digits[:multiplier * j]:
                return j
    assert False, f'Could not find recurrence for {divisor}'

def findit():
    longest_reccuring = (0, 0)
    for i in range(2, 1000):
        _, length = longest_reccuring
        ans = find_recurring_length(i)
        if ans > length:
            longest_reccuring = (i, ans)
            print(f'{ans} > {length} for {i}')


def works():
    assert find_recurring_length(3) == 1, f'{3} != 1'
    print(f'{(3)} works')
    assert find_recurring_length(6) == 1, f'{6} != 1'
    print(f'{(6)} works')
    assert find_recurring_length(7) == 6, f'{7} != 6'
    print(f'{(7)} works')
    assert find_recurring_length(9) == 1, f'{9} != 1'
    print(f'{(9)} works')