| 2. | If we count only once those grids that can be reduced to equivalent configurations , then the number shrinks to 5 , 472 , 730 , 538 ? slightly lower than the population of humans on the earth 但是如果把所有等价的化约形式算成一种,那麽数独终盘的数目就缩减到5 , 472 , 730 , 538种,大概比地球的人口数少一点。 |