一个求集合所有子集的程序，感觉挺巧妙的，效率比较高-Find all subsets of a set of procedures, feeling very clever, more efficient

本算法用于挖掘最大频繁子集，并且找出所有的关联规则-minning maximum frequency subsets,and associate rules

Decision tree builds classification or regression models in the form of a tree structure. It breaks down a dataset into smaller and smaller subsets while at the same time an associated decision tree is incrementally developed. The final result is a t