回複：解釋：|OOO|OOOOOOOOOO|O||OOOOO|.....|OOO|||O|OOOOOOOOO|O|

來源: 於 2010-06-17 08:30:56 [舊帖] [給我悄悄話] 本文已被閱讀：次

m people and n rooms also right,C(m+n-1,n).