用B-树作为查找存储结构，对中文单词进行哈希，用最长逆向匹配算法进行中文句段分词，实现中文词典以及分词。中文词典规模为十万八千多词汇。分词的正确率在90 以上。-Use the B-tree as storage structure , and hash the Chinese word while storing or searching. Use the longest reverse matching algorithm to split Chinese sentence to word