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  1.模式匹配：子串在主串中的定位，也叫字符串匹配。模式匹配成功是指在主串S中能够找到模式串T，否则，称模式串T在主串S中不存在。 2.模式匹配的应用在非常广泛。例如，在文本编辑程序中，我们经常要查找某一特定单词在文本中出现的位置。 3.模式匹配算法的研究能极大地提高文本编辑程序的响应性能。 (1 pattern matching: substring positioned in the main string, also called string matching. Pattern matching refers success can be found in the main string S pattern string T, otherwise known as pattern string T does not exist in the main string S. 2 pattern matching in a very wide range. For example, in a text-editing program, we often have to find the location of a particular word appears in the text. 3 study of pattern matching algorithms can greatly improve the response performance of text editing program.)