Method contains

publication/code/chapter10/trie.rs:34–36

判断单词是否存在

(&self, word: &str)

    // 判断单词是否存在
    fn contains(&self, word: &str) -> bool {
        self.word_node(word).map_or(false, |n| n.end)
    }

    // 判断是否存在以某个前缀开头的单词
    fn start_with(&self, prefix: &str) -> bool {