回複：回複：讓人煩惱的禮金卡問題

來源: 於 2009-01-06 01:54:19 [博客] [舊帖] [給我悄悄話] 本文已被閱讀：次

The optimal solution gets you 1000 * r, where r is the value such that 0
r*(1-r)/(1-0.81*r*r)