The paper introduced the basic conception of math of relation database model,N-ple relation,fordered N-ple and fordered sets.
给出了关系数据库模型的数学基本概念 ,如N元关系、N元有序组及N元有序组集合。
Bisearch algorithm is an important search algorithm in the sequence array of data structure,which most cyclic compared time is └log2n」+1 when algorithm searches a special element among some ones.
折半查找算法是数据结构中有序序列查找中的一个重要算法,此算法在含有n个元素的有序序列中查找某一个元素时,最大循环比较次数为└log2n」+1。