... {[C(N, n1)C(N-n1,n2)..C(N-n1-n2-...n(k-1,nk)/D(n1,n2m,,,nk)]

来源: 于 2012-05-06 09:41:59 [旧帖] [给我悄悄话] 本文已被阅读：次