// [leetcode 208](https://leetcode.com/problems/implement-trie-prefix-tree/)

#[derive(Default, Debug)]
struct Trie {
    is_ending: bool,
    nodes:     [Option<Box<Trie>>; 26],
}

impl Trie {
    fn new() -> Self {
        Default::default()
    }

    fn insert(&mut self, word: &str) {
        let mut curr = self;
        for i in word.chars().map(|c| (c as usize - 'a' as usize) as usize) {
            curr = curr.nodes[i].get_or_insert_with(|| Box::new(Trie::new()));
        }
        curr.is_ending = true;
    }

    fn find(&self, word: &str) -> bool {
        let mut curr = self;
        for i in word.chars().map(|c| (c as usize - 'a' as usize) as usize) {
            match curr.nodes[i].as_ref() {
                Some(node) => { curr = node; },
                None => { return false; },
            }
        }
        curr.is_ending
    }
}

fn main() {
    let mut m = Trie::new();
    m.insert("hello");
    m.insert("she");
    println!("{:?}", m);
    let r = m.search("hello");
    println!("{}", r); // true
}