实现链表的各种操作，如统计文本中单词，数字以及其他符号的个数；求某个单词在文本中出现的所有位置；删除文本中的特定的字符串。(The implementation of the list of various operations, such as statistical text in the word, number, and other symbols of the number; find a word in the text appears in all locations; delete the text of a specific string.)