RosettaCodeData/Task/Non-transitive-dice/Python/non-transitive-dice-1.py

33 lines
1.0 KiB
Python

from itertools import combinations_with_replacement as cmbr
from time import time
def dice_gen(n, faces, m):
dice = list(cmbr(faces, n))
succ = [set(j for j, b in enumerate(dice)
if sum((x>y) - (x<y) for x in a for y in b) > 0)
for a in dice]
def loops(seq):
s = succ[seq[-1]]
if len(seq) == m:
if seq[0] in s: yield seq
return
for d in (x for x in s if x > seq[0] and not x in seq):
yield from loops(seq + (d,))
yield from (tuple(''.join(dice[s]) for s in x)
for i, v in enumerate(succ)
for x in loops((i,)))
t = time()
for n, faces, loop_len in [(4, '1234', 3), (4, '1234', 4), (6, '123456', 3), (6, '1234567', 3)]:
for i, x in enumerate(dice_gen(n, faces, loop_len)): pass
print(f'{n}-sided, markings {faces}, loop length {loop_len}:')
print(f'\t{i + 1}*{loop_len} solutions, e.g. {" > ".join(x)} > [loop]')
t, t0 = time(), t
print(f'\ttime: {t - t0:.4f} seconds\n')