摘要：这道题是水题，发现平移某些边，答案就是圆心的凸包+一个圆的周长。 不要忽视精度误差！ 阅读全文

摘要：There are a lot of trees in an area. A peasant wants to buy a rope to surround all these trees. So at first he must know the minimal required length o 阅读全文

摘要：Matt is a big fan of logo design. Recently he falls in love with logo made up by rings. The following figures are some famous examples you may know.A 阅读全文