又称单词查找树，Trie树，是一种树形结构，是一种哈希树的变种。典型应用是用于统计，排序和保存大量的字符串（但不仅限于字符串），所以经常被搜索引擎系统用于文本词频统计-Also known as word search tree, the trie is a tree structure, which is a variant of the hash tree. Typical applications are used for statistical, sort and save a lot