Euler24

gistfile1.py

from Mathstuff import mathstuff

M = mathstuff()

A = M.permutations(range(9))
print A(10**6-1)

	def permutations(self, iterable):
		return list(set(self.doPermutations(iterable)))
	
	def doPermutations(self, iterable, r=None):
    		pool = tuple(iterable)
    		n = len(pool)
    		if(r is None):
    			r = n
    		if r > n:
        		return
    		indices = range(n)
    		cycles = range(n, n-r, -1)
    		yield tuple(pool[i] for i in indices[:r])
    		while n:
        		for i in reversed(range(r)):
            			cycles[i] -= 1
            			if cycles[i] == 0:
               				indices[i:] = indices[i+1:] + indices[i:i+1]
                			cycles[i] = n - i
            			else:
                			j = cycles[i]
                			indices[i], indices[-j] = indices[-j], indices[i]
                			yield tuple(pool[i] for i in indices[:r])
                			break
        		else:
            			return