其和是101阶乘减1。这个全排列与选排列的关系有什么解释没有？

来源: wxcfan123 于 2022-02-10 20:47:15 [旧帖] [给我悄悄话] 本文已被阅读：次

WENXUECITY.COM does not represent or guarantee the truthfulness, accuracy, or reliability of any of communications posted by other users.