摘要: OverfencingKolstad and Schrijvers Farmer John went crazy and created a huge maze of fences out in a field. Happily, he left out two fence segments on the edges, and thus created two "exits" for the maze. Even more happily, the maze he created by this overfencing experience is a `perfect 阅读全文
posted @ 2012-10-01 12:54 剑不飞 阅读(263) 评论(0) 推荐(0)