Section 2.4 Cow Tours 参考[1]写了详细的解题过程。另外,浮点数要用double 参考: [1]http://qxavier.info/2011/01/25/usaco-section-2-4-cow-tours/ [2]http://www.cppblog.com/yuziyu/archive/2009/06/27/88662.html