# z_fast_permute.py

# z_fast_permute.py

def permute(zzz):
    if len(zzz) == 1:
        return [zzz]
    return [[zzz[i]] + p for i in range(len(zzz)) for p in permute(zzz[:i] + zzz [i+1:])]

for zzz in permute([1,2,3,4]):
    print ''.join(str(z) for z in zzz),

'1234 1243 1324 1342 1423 1432 2134 2143 2314 2341 2413 2431 3124 3142 3214 3241 3412 3421 4123 4132 4213 4231 4312 4321'