check integer divisible by 3 using finite state machine

divisible-by-3-fsm.y

#! /usr/bin/env python
# -*- coding: utf-8 -*-
# vim:fenc=utf-8
#
# Copyright © 2013 KuoE0 <kuoe0.tw@gmail.com>
#
# Distributed under terms of the MIT license.

"""

"""
table = [[0, 1], [2, 0], [1, 2]]

def stat_transfer_recursion(stat, x):
    if x > 0:
        return stat_transfer(table[stat][x & 1], x >> 1)
    return stat

def stat_transfer_iteration(stat, x):
    stat = 0
    while x > 0:
        stat = table[stat][x & 1]
        x = x >> 1

    return stat


def divisible_3(x):
    return stat_transfer_iteration(0, x) == 0

if __name__ == "__main__":
    import sys
    for i in range(int(sys.argv[1])):
        print i, divisible_3(i)