回複：奧數題：怎樣畫21根直線和118個交點

來源: passenger101 於 2009-03-26 12:22:11 [] [博客] [舊帖] [給我悄悄話] 閱讀數 : (245 bytes)

10x10 grid give 100交點

find 1交點on two opposite edges. draw the last line through these 2交點. Make sure not hit any other 交點 or simply pick up 2 corner points of biggest rectangle that is made by two adjacent parallel lines.

請您先登陸，再發跟帖！