题目网址: http://www.puzzleup.com/2017/ http://www.puzzleup.com/2017/puzzle/?9 答题时限: 10月５日７ＰＭ－比赛结束（约12月27日） 加分时限: 10月５日７ＰＭ－10月10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）　　 ◆CROSSING POINTS Place seven points on a plane such that no three are collinear, then connect every pair with a curve (can be a straight line). On every crossing point except the initial seven points at most two curves can intersect. What is the minimum number of these crossing points? 将七个点放在平面上，使得任三点不共线，然後将每一对以曲线连线(可以是直线)。 所有这些线的交点，除了原来的七个点之外，至多有两条曲线相交。 试问这些交点数目至少有多少？ -- Ace Snake Santa Clover Junpei June Seven Lotus 9th man cabin kitchen casino shower operating room laboratory Ｔ Ｈ Ｅ chart captain quarter confinement torture room steam engine room cargo chapel library study incinerator Gigantic Q director office security Ｎ Ｏ Ｎ Ａ Ｒ Ｙ archives control laboratory pec treatment garden pantry gaulem bay rec room crew quarters infirmary lounge elevator Tenmyouji Quark Dio Ｇ Ａ Ｍ Ｅ Ｓ Luna Phi Sigma Alice Clover K --

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