self_counting.py

gistfile1.py

import sys
import unittest

# 100000000 means 1 one and 0 of anything else, up to 9.

def is_self_counting(number, max):
	lookup = [1,2,3,4,5,6,7,8,9,0]
	print "Checking", number
	for i in range(0,max):
		count = number.count(lookup[i])
		if count <> number[i]:
			return False
	return True

def find_self_counting(max):
	print "from", 10**(max-1), "to", 10**max - 1, "using max", max

	#for i in xrange(10**(max-1),10**max):
	for i in xrange(0,1000000000):
		l = to_string(i, max)
		#print i, l
		if sum(l) <= max:
			if is_self_counting(l, max):
				print "self counting", i 


def to_string(i, max):
	pos = 0
	l = [0 for t in range (0,max)]
	for c in str(i):
		l[pos] = int(c)
		pos = pos + 1
	return l


class SelfCountingTests(unittest.TestCase):
	def test_that_known_ten_digit_number_is_self_counting_for_max_10(self):
		i = 2100010006
		max = 10
		l = to_string(i, max)
		self.assertTrue(is_self_counting(l, max))

	def test_that_known_one_digit_number_is_self_counting_for_max_1(self):
		i = 1
		max = 1
		l = to_string(i, max)
		self.assertTrue(is_self_counting(l, max))

	def test_that_2_is_not_self_counting_for_max_1(self):
		i = 2
		max = 1
		l = to_string(i, max)
		self.assertFalse(is_self_counting(l, max))

	def test_that_known_nine_digit_number_is_self_counting_for_max_9(self):
		i = 100000000
		max = 9
		l = to_string(i, max)
		self.assertTrue(is_self_counting(l, max))

	def test_that_123456789_is_not_self_counting_for_max_9(self):
		i = 123456789
		max = 9
		l = to_string(i, max)
		self.assertFalse(is_self_counting(l, max))


if __name__ == "__main__":
	if len(sys.argv) > 1 and sys.argv[1] == "--test":
		unittest.main(argv = sys.argv[1:])
	else:
		find_self_counting(9)