简单的txt文本搜索程序。能够从指定的txt文档中搜索特定单词并生成其KWIC。此程序为《统计自然语言处理基础》习题1.6第7题答案。-Simple search program for certain word in a txt file. It can find out specific word in a txt file and generate its KWIC. This program can serve as the answer of practice 1.6.7 of "Fo