結果

問題 No.1641 Tree Xor Query
コンテスト
ユーザー fukafukatani
提出日時 2021-08-06 23:10:11
言語 Rust
(1.83.0 + proconio)
結果
AC  
実行時間 259 ms / 5,000 ms
コード長 3,559 bytes
コンパイル時間 13,498 ms
コンパイル使用メモリ 379,844 KB
実行使用メモリ 23,312 KB
最終ジャッジ日時 2024-09-17 03:25:54
合計ジャッジ時間 15,766 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge2
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 * 3
other AC * 18
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: `i`
  --> src/main.rs:23:9
   |
23 |     for i in 0..n - 1 {
   |         ^ help: if this is intentional, prefix it with an underscore: `_i`
   |
   = note: `#[warn(unused_variables)]` on by default

warning: unused variable: `i`
  --> src/main.rs:30:9
   |
30 |     for i in 0..q {
   |         ^ help: if this is intentional, prefix it with an underscore: `_i`

ソースコード

diff # 

#![allow(unused_imports)]
use std::cmp::*;
use std::collections::*;
use std::io::Write;
use std::ops::Bound::*;

#[allow(unused_macros)]
macro_rules! debug {
    ($($e:expr),*) => {
        #[cfg(debug_assertions)]
        $({
            let (e, mut err) = (stringify!($e), std::io::stderr());
            writeln!(err, "{} = {:?}", e, $e).unwrap()
        })*
    };
}

fn main() {
    let v = read_vec::<usize>();
    let (n, q) = (v[0], v[1]);
    let c = read_vec::<i64>();
    let mut edges = vec![vec![]; n];
    for i in 0..n - 1 {
        let v = read_vec::<usize>();
        let (a, b) = (v[0] - 1, v[1] - 1);
        edges[a].push(b);
        edges[b].push(a);
    }
    let mut queries = vec![];
    for i in 0..q {
        let v = read_vec::<i64>();
        let (t, x, y) = (v[0], v[1] as usize - 1, v[2]);
        queries.push((t, x, y));
    }

    let mut pre_order = vec![0usize; n];
    let mut post_order = vec![0usize; n];
    dfs(0, 0, &edges, &mut 0, &mut pre_order, &mut post_order);
    debug!(pre_order);
    debug!(post_order);
    let mut seg = SegTree::new(n, 0i64, |x, y| x ^ y);
    for i in 0..n {
        seg.update(pre_order[i], c[i]);
    }

    for (t, x, y) in queries {
        if t == 1 {
            let val = seg.query(pre_order[x], pre_order[x] + 1);
            seg.update(pre_order[x], val ^ y);
        } else {
            let ans = seg.query(pre_order[x], post_order[x]);
            println!("{}", ans);
        }
    }
}

fn dfs(
    cur: usize,
    parent: usize,
    edges: &Vec<Vec<usize>>,
    count: &mut usize,
    pre_order: &mut Vec<usize>,
    post_order: &mut Vec<usize>,
) {
    pre_order[cur] = *count;
    *count += 1;
    for &to in edges[cur].iter().filter(|&&x| x != parent) {
        dfs(to, cur, edges, count, pre_order, post_order);
    }
    post_order[cur] = *count;
}

fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}

#[derive(Clone)]
struct SegTree<T, F>
where
    F: Fn(T, T) -> T,
    T: std::clone::Clone + std::marker::Copy,
{
    n: usize,
    dat: Vec<T>,
    init: T,
    functor: F,
}

impl<T, F> SegTree<T, F>
where
    F: Fn(T, T) -> T,
    T: std::clone::Clone + std::marker::Copy,
{
    fn new(n: usize, init: T, f: F) -> SegTree<T, F> {
        let mut m = 1;
        // For simplicity, we use 2 ** n sized SegTree.
        while m < n {
            m *= 2;
        }
        SegTree {
            n: m,
            dat: vec![init; 2 * m - 1],
            init: init,
            functor: f,
        }
    }

    // dat[k] = a;
    fn update(&mut self, k: usize, a: T) {
        let mut k = k;
        k += self.n - 1;
        self.dat[k] = a;
        while k > 0 {
            k = (k - 1) / 2;
            self.dat[k] = (self.functor)(self.dat[k * 2 + 1], self.dat[k * 2 + 2]);
        }
    }

    // [a, b)
    fn query(&self, a: usize, b: usize) -> T {
        self.query_inner(a, b, 0, 0, self.n)
    }

    fn query_inner(&self, a: usize, b: usize, k: usize, l: usize, r: usize) -> T {
        if r <= a || b <= l {
            return self.init;
        }
        if a <= l && r <= b {
            return self.dat[k];
        }

        let vl = self.query_inner(a, b, k * 2 + 1, l, (l + r) / 2);
        let vr = self.query_inner(a, b, k * 2 + 2, (l + r) / 2, r);
        (self.functor)(vl, vr)
    }
}
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