又称Levenshtein距离（也叫做Edit Distance），是指两个字串之间，由一个转成另一个所需的最少编辑操作次数。许可的编辑操作包括将一个字符替换成另一个字符，插入一个字符，删除一个字符。 -Also known as Levenshtein distance (also known as Edit Distance), is between two strings, one by one turned into the minimum required number of editing operations. Editing operation permit include replacing one character to another character, insert a character, delete a character.