为什么要研究查找？

查找（Searching,又称检索或搜索）无论是在日常生活

中，还是在计算机的系统软件和应用软件都会广泛涉及到。信息检索已经成为计算机应用领域中的一个方面。当所要查找数据量相当大时，寻找一种高效的查找方法就显得尤为重要。如果数据元素或记录项很多以至于内存都无法存放所有的数据元素或记录，则有必要把一些数据元素存储到磁盘或磁带上去，在这种情况下的查找叫做外部查找；而如果所需要的查找的数据元素都在内存中，则称这种情况下的查找为内部查找（这里只考虑内部查找，当然有些算法在外部查找中同样适用）。

-Why study?



Search ( Searching, also known as retrieval or search ) in our daily life



, or in computer system software and application software are widely involved. Information retrieval has become the computer application in the field of hand. When the data amount is quite large, find an efficient search method is particularly important. If the data elements or record a lot of that memory can store all data elements or recording, it is necessary to put some data elements stored to disk or tape up, in this case search is called external searching　and if the lookup data elements in memory, said this case search for internal search ( here only consider internal search, of course, some algorithms in external search applies ).