#1174608 (Rust) No.3606 Ice Grid Game

• 問題: No.3606 Ice Grid Game
• ユーザー: akakimidori
• 提出日時: 2026-07-31 23:18:51
• 言語: Rust (1.94.0 + proconio + num + itertools)
• 結果: AC
• 実行時間: 53 ms / 2,000 ms
• コード長: 3,955 bytes
• コンパイル時間: 11,927 ms
• コンパイル使用メモリ: 196,280 KB
• 実行使用メモリ: 56,832 KB
• 最終ジャッジ日時: 2026-07-31 23:19:11
• 合計ジャッジ時間: 13,212 ms
• ジャッジサーバーID （参考情報）: judge2_0 / judge3_1

ファイルパターン	結果
sample	AC * 1
other	AC * 11

コンパイルメッセージ

warning: type alias `Map` is never used
 --> src/main.rs:4:6
  |
4 | type Map<K, V> = BTreeMap<K, V>;
  |      ^^^
  |
  = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default

warning: type alias `Set` is never used
 --> src/main.rs:5:6
  |
5 | type Set<T> = BTreeSet<T>;
  |      ^^^

warning: type alias `Deque` is never used
 --> src/main.rs:6:6
  |
6 | type Deque<T> = VecDeque<T>;
  |      ^^^^^

ソースコード

use std::io::Write;
use std::collections::*;

type Map<K, V> = BTreeMap<K, V>;
type Set<T> = BTreeSet<T>;
type Deque<T> = VecDeque<T>;

fn run() {
    input! {
        t: usize,
        ask: [(usize, usize, usize1, usize1); t],
    }
    let out = std::io::stdout();
    let mut out = std::io::BufWriter::new(out.lock());
    for (h, w, r, c) in ask {
        let mut b = vec![vec![false; w]; h];
        b[r][c] = true;
        let g = Grid::new(h, w);
        let ans = if g.neighbor(r, c).any(|(x, y)| {
            !dfs((r, c), (x, y), &g, &mut b)
        }) {"Alice"} else {"Bob"};
        writeln!(out, "{}", ans).ok();
    }
}

fn dfs(src: (usize, usize), dst: (usize, usize), g: &Grid, b: &mut [Vec<bool>]) -> bool {
    let mut pos = dst;
    let h = b.len();
    let w = b[0].len();
    while pos.0 < h && pos.1 < w && !b[pos.0][pos.1] {
        b[pos.0][pos.1] = true;
        pos.0 += dst.0 - src.0;
        pos.1 += dst.1 - src.1;
    }
    pos.0 -= dst.0 - src.0;
    pos.1 -= dst.1 - src.1;
    let res = g.neighbor(pos.0, pos.1).any(|p| {
        !b[p.0][p.1] && !dfs(pos, p, g, b)
    });
    pos.0 += dst.0 - src.0;
    pos.1 += dst.1 - src.1;
    let save = pos;
    pos = dst;
    while pos.0 < h && pos.1 < w && pos != save {
        b[pos.0][pos.1] = false;
        pos.0 += dst.0 - src.0;
        pos.1 += dst.1 - src.1;
    }
    res
}

fn main() {
    run();
}

#[derive(Clone)]
pub struct Grid {
    h: usize,
    w: usize,
}

impl Grid {
    pub fn new(h: usize, w: usize) -> Self {
        Self { h, w }
    }
    pub fn neighbor(&self, x: usize, y: usize) -> impl Iterator<Item = (usize, usize)> + '_ {
        const DX: [usize; 4] = [0, 1, 0, !0];
        const DY: [usize; 4] = [1, 0, !0, 0];
        self.generator(x, y, DX.iter().zip(DY.iter()).map(|p| (*p.0, *p.1)))
    }
    pub fn king(&self, x: usize, y: usize) -> impl Iterator<Item = (usize, usize)> + '_ {
        const DX: [usize; 8] = [0, 1, 1, 1, 0, !0, !0, !0];
        const DY: [usize; 8] = [1, 1, 0, !0, !0, !0, 0, 1];
        self.generator(x, y, DX.iter().zip(DY.iter()).map(|p| (*p.0, *p.1)))
    }
    pub fn generator<'a, I>(
        &'a self,
        x: usize,
        y: usize,
        it: I,
    ) -> impl Iterator<Item = (usize, usize)> + 'a
    where
        I: Iterator<Item = (usize, usize)> + 'a,
    {
        it.map(move |p| (x.wrapping_add(p.0), y.wrapping_add(p.1)))
            .filter(|p| p.0 < self.h && p.1 < self.w)
    }
}

// 手で試した感じ分岐が定数個？

// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
#[macro_export]
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

#[macro_export]
macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};
    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

#[macro_export]
macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, bytes) => {
        read_value!($iter, String).bytes().collect::<Vec<u8>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}
// ---------- end input macro ----------