回複:一道中學的排列組合題

來源: 2009-10-08 13:28:38 [舊帖] [給我悄悄話] 本文已被閱讀:

13!/(2!2!2!2!)-4*12!/(2!2!2!)+16*10!/(2!2!)-24*8!/2+24*6!