题目网址: http://www.puzzleup.com/2014/
http://www.puzzleup.com/2014/puzzle/?255
答题时限: 10月30日７ＰＭ－比赛结束（约12月17日）
加分时限: 10月30日７ＰＭ－11月５日６：５９ＰＭ
答对可得基本分１００分。答案可上传５次，每改１次答案从基本分扣２０分。　
比赛期间内可随时上传答案，加分时限内答对第ｎ天加（６－ｎ）分　 　　 　　
另依题目的难易有额外加分（如有８０％的人这题答错，答对者加８０分）　　
◆Five Points
http://www.puzzleup.com/2014/img/puzzle/2014/14.jpg
You will connect the five points given in the figure (the vertices of regular
pentagon) by drawing straight lines.
-You will visit each of the points exactly one time.
-You won’t lift your pencil from the paper while drawing.
-You can cross over the lines.
How many diferent shapes can be obtained?
Notes:
-Rotations and reflections will be counted seperately.
-A shape can not be counted as a new shape if it is obtained by just
changing the direction of the drawing betwen the two terminal points.
Four of shapes included in the solution are shown below.
你要将如上图的五点 (形成一个正五边形) 画直线段连接起来。
* 你将经过每个点正好一次。
* 连接时笔尖不离开纸面。
* 直线段之间可以交叉。
试问可以得到多少种图形？
注:
* 旋转及镜像分开计算。
* 若仅仅是改变线段画的方向则不算新图形。
以下为其中四种图形：
http://www.puzzleup.com/2014/img/puzzle/2014/14_ek.jpg