按tf-idf在剔除一些常用词后给出文本中术语的统计算法和程序，并按降序进行排序,另外，对文档建立inverted file，然后进行检索的算法-Tf-idf removed by a number of commonly used words in the text given after the algorithm in terms of statistics and procedures, according to descending order, in addition, the document build inverted file, and then search algorithm