摘要：1. C++中格式控制在C++中，说到保留小数点后几位有效数字，就会想起setprecision,马上去cplusplus上查了下有关setprecision的资料，看了后明白了，懒得逐字翻译，直接贴在下面了：Set decimal precisionSets the decimal precision to be used by output operations.Behaves as if a call to the stream's member ios_base::precision with n as argument was made.The decimal precisi 阅读全文