说明：  此代码是线段树的实现源代码，可用O（nlogn）的时间查找出一段线段中任意一段的信息。做acm题很有用，应用程序中相信也能优化很多算法！
(This code is a segment tree realize the source code can be O (nlogn) time to search out a section of line segments in arbitrary information. Acm title make useful applications, many believe that the optimization algorithm can be!)