結果

問題 No.3258 Xor Division Game
ユーザー koba-e964
提出日時 2025-10-17 16:45:20
言語 Rust
(1.83.0 + proconio)
結果
RE  
実行時間 -
コード長 3,503 bytes
コンパイル時間 11,528 ms
コンパイル使用メモリ 400,272 KB
実行使用メモリ 9,232 KB
最終ジャッジ日時 2025-10-17 16:45:42
合計ジャッジ時間 16,832 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge3
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 2
other AC * 32 WA * 6 RE * 29
権限があれば一括ダウンロードができます
コンパイルメッセージ
warning: unused variable: `n`
   --> src/main.rs:104:9
    |
104 |     let n = a.len();
    |         ^ help: if this is intentional, prefix it with an underscore: `_n`
    |
    = note: `#[warn(unused_variables)]` on by default

warning: variable `seen` is assigned to, but never used
   --> src/main.rs:105:13
    |
105 |     let mut seen = s.l;
    |             ^^^^
    |
    = note: consider using `_seen` instead

warning: value assigned to `seen` is never read
   --> src/main.rs:111:9
    |
111 |         seen = idx + 1;
    |         ^^^^
    |
    = help: maybe it is overwritten before being read?
    = note: `#[warn(unused_assignments)]` on by default

warning: function `facil` is never used
  --> src/main.rs:17:4
   |
17 | fn facil(a: &[u32], l: usize, r: usize) -> Stat {
   |    ^^^^^
   |
   = note: `#[warn(dead_code)]` on by default

ソースコード

diff # 

use std::collections::*;

fn getline() -> String {
    let mut ret = String::new();
    std::io::stdin().read_line(&mut ret).unwrap();
    ret
}

#[derive(Debug)]
struct Stat {
    l: usize,
    r: usize,
    unique: BTreeSet<usize>, // index
    freq: HashMap<u32, i32>,
}

fn facil(a: &[u32], l: usize, r: usize) -> Stat {
    let b = &a[l..r];
    let mut freq = HashMap::new();
    for &f in b {
        *freq.entry(f).or_insert(0) += 1;
    }
    let stat = Stat {
        l,
        r,
        unique: {
            let mut x = BTreeSet::new();
            for i in l..r {
                if freq[&a[i]] == 1 {
                    x.insert(i);
                }
            }
            x
        },
        freq,
    };
    stat
}

fn split(a: &[u32], mut s: Stat, idx: usize) -> (Stat, Stat) {
    let val = a[idx];
    assert_eq!(s.freq[&val], 1);
    s.freq.remove(&val);
    s.unique.remove(&idx);
    let mut new = Stat {
        l: s.l,
        r: s.r,
        unique: BTreeSet::new(),
        freq: HashMap::new(),
    };
    if 2 * idx >= s.l + s.r {
        for i in idx + 1..s.r {
            let f = a[i];
            let c = s.freq.get(&f).cloned().unwrap_or(0);
            if c > 0 {
                *s.freq.get_mut(&f).unwrap() -= 1;
                if c == 1 {
                    s.freq.remove(&f);
                    s.unique.remove(&i);
                }
                if c == 2 {
                    s.unique.insert(i);
                }
            }
            let c = new.freq.get(&f).cloned().unwrap_or(0);
            *new.freq.entry(f).or_insert(0) += 1;
            if c == 0 {
                new.unique.insert(i);
            } else if c == 1 {
                new.unique.remove(&i);
            }
        }
        new.l = idx + 1;
        s.r = idx;
        return (s, new);
    }
    for i in s.l..idx {
        let f = a[i];
        let c = s.freq.get(&f).cloned().unwrap_or(0);
        if c > 0 {
            *s.freq.get_mut(&f).unwrap() -= 1;
            if c == 1 {
                s.freq.remove(&f);
                s.unique.remove(&i);
            }
            if c == 2 {
                s.unique.insert(i);
            }
        }
        let c = new.freq.get(&f).cloned().unwrap_or(0);
        *new.freq.entry(f).or_insert(0) += 1;
        if c == 0 {
            new.unique.insert(i);
        } else if c == 1 {
            new.unique.remove(&i);
        }
    }
    new.r = idx;
    s.l = idx + 1;
    (new, s)
}

fn rec(a: &[u32], mut s: Stat) -> i32 {
    let n = a.len();
    let mut seen = s.l;
    let mut ans = 0;
    while let Some(&idx) = s.unique.first() {
        let (t, tmp) = split(a, s, idx);
        ans += rec(a, t) + 1;
        s = tmp;
        seen = idx + 1;
    }
    // eprintln!("stat = {s:?}, ans = {ans}");
    ans
}

// https://yukicoder.me/problems/no/3258 (3.5)
fn main() {
    getline();
    let f = getline().trim().split_whitespace()
        .map(|x| x.parse::<u32>().unwrap())
        .collect::<Vec<_>>();
    let n = f.len();
    let mut freq = HashMap::new();
    for &f in &f {
        *freq.entry(f).or_insert(0) += 1;
    }
    let stat = Stat {
        l: 0,
        r: n,
        unique: {
            let mut x = BTreeSet::new();
            for i in 0..n {
                if freq[&f[i]] == 1 {
                    x.insert(i);
                }
            }
            x
        },
        freq,
    };
    println!("{}", if rec(&f, stat) % 2 == 1 {
        "Alice"
    } else {
        "Bob"
    });
}
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