Division without arithmetic operators

gistfile1.py

#!/usr/bin/env python

def slow_divide(x, y):
	res = 0
	while x >= y:
		x = x - y
		res += 1
	return res

def divide(x, y):
	# Based on the fact that x/y = (n*y + x - n*y) /y = n + (x - n*y)/y
	# where n can be anything. In particular n = 2^i
	if x <= (y << 1):
		return slow_divide(x, y)
	
	quotient = 1
	factor   = y
	while factor <= x:
		factor   = factor << 1
		quotient = quotient << 1
	
	# factor is bigger than x now, so go back once
	factor   = factor >> 1
	quotient = quotient >> 1
	
	return quotient + slow_divide(x - factor, y)