Submission #5028951


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use std::collections::{BTreeMap, BTreeSet};

fn main() {
    let s = std::io::stdin();
    let mut sc = Scanner { stdin: s.lock() };
    let n: usize = sc.read();
    let l: u64 = sc.read();
    let mut trie = Trie {
        nodes: vec![[0; 2]],
    };
    for _ in 0..n {
        let s: Vec<usize> = sc
            .chars()
            .into_iter()
            .map(|c| c as usize - '0' as usize)
            .collect();
        trie.add(&s, 0, 0);
    }

    let mut results = vec![];
    trie.traverse(0, &mut results, l);
    println!(
        "{}",
        if results
            .into_iter()
            .map(|h| 1 << h.trailing_zeros())
            .fold(0, |xor, x| xor ^ x)
            == 0
        {
            "Bob"
        } else {
            "Alice"
        }
    );
}

struct Trie {
    nodes: Vec<[usize; 2]>,
}

impl Trie {
    fn add(&mut self, s: &[usize], pos: usize, cur: usize) {
        if pos == s.len() {
            return;
        }
        if self.nodes[cur][s[pos]] == 0 {
            self.nodes[cur][s[pos]] = self.nodes.len();
            self.nodes.push([0; 2]);
        }
        self.add(s, pos + 1, self.nodes[cur][s[pos]]);
    }

    fn traverse(&self, cur: usize, results: &mut Vec<u64>, height: u64) {
        let [a, b] = self.nodes[cur];
        if a == 0 && b == 0 {
            return;
        }
        if a == 0 || b == 0 {
            results.push(height);
        }
        if a != 0 {
            self.traverse(a, results, height - 1);
        }
        if b != 0 {
            self.traverse(b, results, height - 1);
        }
    }
}

fn grundy(l: usize, map: &mut BTreeMap<usize, usize>) -> usize {
    match map.get(&l) {
        Some(&x) => x,
        None => {
            let mut set = BTreeSet::new();
            for i in 1..(l + 1) {
                let mut g = 0;
                for j in 1..i {
                    g ^= grundy(l - j, map);
                }
                set.insert(g);
            }
            let g = (0..).find(|x| !set.contains(x)).unwrap();
            map.insert(l, g);
            g
        }
    }
}

pub struct Scanner<R> {
    stdin: R,
}

impl<R: std::io::Read> Scanner<R> {
    pub fn read<T: std::str::FromStr>(&mut self) -> T {
        use std::io::Read;
        let buf = self
            .stdin
            .by_ref()
            .bytes()
            .map(|b| b.unwrap())
            .skip_while(|&b| b == b' ' || b == b'\n' || b == b'\r')
            .take_while(|&b| b != b' ' && b != b'\n' && b != b'\r')
            .collect::<Vec<_>>();
        unsafe { std::str::from_utf8_unchecked(&buf) }
            .parse()
            .ok()
            .expect("Parse error.")
    }
    pub fn vec<T: std::str::FromStr>(&mut self, n: usize) -> Vec<T> {
        (0..n).map(|_| self.read()).collect()
    }
    pub fn chars(&mut self) -> Vec<char> {
        self.read::<String>().chars().collect()
    }
}

Submission Info

Submission Time
Task E - Prefix-free Game
User kenkoooo
Language Rust (1.15.1)
Score 0
Code Size 3009 Byte
Status

Compile Error

error: slice pattern syntax is experimental (see issue #23121)
  --> ./Main.rs:54:13
   |
54 |         let [a, b] = self.nodes[cur];
   |             ^^^^^^

error: aborting due to previous error