文本分类，包括：文本预处理，去除停用词，学习和训练，最后实现分类。-Text classification, including: text pre-processing, removal of stop words, learning and training, and finally achieve the classification.

mini搜索引擎，载入50个文本文件，然后通过输入关键词来计算词出现的次数-we will design and implement a mini search engine that is used to search through a set of 50 documents and a set of sample queries. The data structures used for storing is vector and array. The algorithm in this