m people and n rooms: C(m+n-1,m), instead of C(m+n-1,n).

來源: 於 2010-06-17 10:00:40 [博客] [舊帖] [給我悄悄話] 本文已被閱讀：次

C(m+n-1,m) = C(m+n-1,n-1)