結果

問題 No.1582 Vertexes vs Edges
ユーザー koba-e964
提出日時 2021-12-10 00:47:13
言語 Rust
(1.83.0 + proconio)
結果
AC  
実行時間 45 ms / 2,000 ms
コード長 2,666 bytes
コンパイル時間 20,699 ms
コンパイル使用メモリ 395,232 KB
実行使用メモリ 12,416 KB
最終ジャッジ日時 2025-01-27 19:39:03
合計ジャッジ時間 17,553 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge4
このコードへのチャレンジ
（要ログイン）
ファイルパターン 結果
sample AC * 3
other AC * 36
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 import: `BufWriter`
 --> src/main.rs:5:22
  |
5 | use std::io::{Write, BufWriter};
  |                      ^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

warning: unused import: `Write`
 --> src/main.rs:5:15
  |
5 | use std::io::{Write, BufWriter};
  |               ^^^^^

warning: trait `Change` is never used
  --> src/main.rs:46:7
   |
46 | trait Change { fn chmax(&mut self, x: Self); fn chmin(&mut self, x: Self); }
   |       ^^^^^^
   |
   = note: `#[warn(dead_code)]` on by default

ソースコード

diff #
プレゼンテーションモードにする

#[allow(unused_imports)]
use std::cmp::*;
#[allow(unused_imports)]
use std::collections::*;
use std::io::{Write, BufWriter};
// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    ($($r:tt)*) => {
        let stdin = std::io::stdin();
        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
        let mut next = move || -> String{
            bytes.by_ref().map(|r|r.unwrap() as char)
                .skip_while(|c|c.is_whitespace())
                .take_while(|c|!c.is_whitespace())
                .collect()
        };
        input_inner!{next, $($r)*}
    };
}
macro_rules! input_inner {
    ($next:expr) => {};
    ($next:expr,) => {};
    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };
}
macro_rules! read_value {
    ($next:expr, ( $($t:tt),* )) => { ($(read_value!($next, $t)),*) };
    ($next:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    };
    ($next:expr, chars) => {
        read_value!($next, String).chars().collect::<Vec<char>>()
    };
    ($next:expr, usize1) => (read_value!($next, usize) - 1);
    ($next:expr, [ $t:tt ]) => {{
        let len = read_value!($next, usize);
        read_value!($next, [$t; len])
    }};
    ($next:expr, $t:ty) => ($next().parse::<$t>().expect("Parse error"));
}
trait Change { fn chmax(&mut self, x: Self); fn chmin(&mut self, x: Self); }
impl<T: PartialOrd> Change for T {
    fn chmax(&mut self, x: T) { if *self < x { *self = x; } }
    fn chmin(&mut self, x: T) { if *self > x { *self = x; } }
}
fn main() {
    // In order to avoid potential stack overflow, spawn a new thread.
    let stack_size = 104_857_600; // 100 MB
    let thd = std::thread::Builder::new().stack_size(stack_size);
    thd.spawn(|| solve()).unwrap().join().unwrap();
}
const INF: i64 = 1 << 50;
fn dfs(v: usize, par: usize, g: &[Vec<usize>], dp: &mut [[i64; 2]]) {
    let mut me = [-INF; 2];
    let mut s = 0;
    let mut mi = INF;
    for &w in &g[v] {
        if w == par { continue; }
        dfs(w, v, g, dp);
        let poss = max(dp[w][0], dp[w][1]);
        s += poss;
        mi = min(mi, poss - dp[w][0]);
    }
    me[0] = s;
    me[1] = s - mi + 1;
    dp[v] = me;
}
// Tags: max-matching-on-trees
fn solve() {
    input! {
        n: usize,
        ab: [(usize1, usize1); n - 1],
    }
    let mut g = vec![vec![]; n];
    for &(a, b) in &ab {
        g[a].push(b);
        g[b].push(a);
    }
    let mut dp = vec![[-INF; 2]; n];
    dfs(0, n, &g, &mut dp);
    println!("{}", max(dp[0][0], dp[0][1]));
}
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
0