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题目：http://ace.delos.com/usacoprob2?a=m0gi84wTGvp&S=fence8http://pingce.ayyz.cn:9000/usaco/data/20110129214306/fence8.htmlFence RailsBurch, Kolstad, and SchrijversFarmer John is trying to erect a fence around part of his field. He has decided on the shape of the fence and has even already install 阅读全文
摘要：
题目：http://ace.delos.com/usacoprob2?a=hgHbW0wyBLd&S=fence4http://www.nocow.cn/index.php/Translate:USACO/fence4Closed FencesA closed fence in the plane is a set of non-crossing, connected line segments with N corners (3 < N < 200). The corners or vertices are each distinct and are listed in 阅读全文