#1196145 (Rust) No.3781 Erase One, Gain from the Other

• 問題: No.3781 Erase One, Gain from the Other
• ユーザー: akakimidori
• 提出日時: 2026-10-30 23:15:28
• 言語: Rust (1.99.0 + proconio + num + itertools + ACL)
• 結果: AC
• 実行時間: 56 ms / 2,000 ms
• コード長: 4,213 bytes
• コンパイル時間: 4,337 ms
• コンパイル使用メモリ: 195,756 KB
• 実行使用メモリ: 24,016 KB
• 最終ジャッジ日時: 2026-10-30 23:15:45
• 合計ジャッジ時間: 10,918 ms
• ジャッジサーバーID （参考情報）: judge4_0 / judge7_0

ファイルパターン	結果
sample	AC * 1
other	AC * 34

コンパイルメッセージ

warning: use of deprecated constant `std::i32::MAX`: replaced by the `MAX` associated constant on this type
   --> src/main.rs:103:31
    |
103 |         assert!(n < std::i32::MAX as usize);
    |                               ^^^
    |
    = note: `#[warn(deprecated)]` on by default

warning: type alias `Map` is never used
  --> src/main.rs:84:6
   |
84 | 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:85:6
   |
85 | type Set<T> = BTreeSet<T>;
   |      ^^^

warning: type alias `Deque` is never used
  --> src/main.rs:86:6
   |
86 | type Deque<T> = VecDeque<T>;
   |      ^^^^^

ソースコード

fn run<W: Write>(sc: &mut scanner::Scanner, out: &mut std::io::BufWriter<W>) {
    let t: u32 = sc.next();
    for _ in 0..t {
        let n: usize = sc.next();
        let m: usize = sc.next();
        let mut a = sc.next_vec::<i64>(n);
        a.insert(0, 0);
        let mut e = vec![(0, 0, 0); m];
        for e in e.iter_mut() {
            let x = sc.next::<usize>();
            let y = sc.next::<usize>();
            *e = (a[x] + a[y], x, y);
        }
        e.extend((1..=n).map(|i| (a[i], 0, i)));
        e.sort();
        let mut dsu = DSU::new(n + 1);
        let mut ans = -a.iter().sum::<i64>();
        for (w, a, b) in e.into_iter().rev() {
            if dsu.unite(a, b).is_some() {
                ans += w;
            }
        }
        writeln!(out, "{}", ans).ok();
    }
}

/*

誤読
黒くするのとは逆の頂点の値だけの点が入る

木の場合は解ける？
辺に向きつける、出次数*頂点の値の分だけ点が入る
本当か？
-> o <-
という形もng

木を塗り切るのは可能
根一つだけではない、サンプル1

ある木のスコア
A_v + A_u の和 - sum A + max A

max?

超頂点0作ってA_0=0とすれば最大全域木になってる？
その場合はmaxはいらない

*/

// ---------- begin scannner ----------
#[allow(dead_code)]
mod scanner {
    use std::str::FromStr;
    pub struct Scanner<'a> {
        it: std::str::SplitWhitespace<'a>,
    }
    impl<'a> Scanner<'a> {
        pub fn new(s: &'a String) -> Scanner<'a> {
            Scanner {
                it: s.split_whitespace(),
            }
        }
        pub fn next<T: FromStr>(&mut self) -> T {
            self.it.next().unwrap().parse::<T>().ok().unwrap()
        }
        pub fn next_bytes(&mut self) -> Vec<u8> {
            self.it.next().unwrap().bytes().collect()
        }
        pub fn next_chars(&mut self) -> Vec<char> {
            self.it.next().unwrap().chars().collect()
        }
        pub fn next_vec<T: FromStr>(&mut self, len: usize) -> Vec<T> {
            (0..len).map(|_| self.next()).collect()
        }
    }
}
// ---------- end scannner ----------

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 main() {
    use std::io::Read;
    let mut s = String::new();
    std::io::stdin().read_to_string(&mut s).unwrap();
    let mut sc = scanner::Scanner::new(&s);
    let out = std::io::stdout();
    let mut out = std::io::BufWriter::new(out.lock());
    run(&mut sc, &mut out);
}
//---------- begin union_find ----------
pub struct DSU {
    p: Vec<i32>,
}
impl DSU {
    pub fn new(n: usize) -> DSU {
        assert!(n < std::i32::MAX as usize);
        DSU { p: vec![-1; n] }
    }
    pub fn init(&mut self) {
        self.p.iter_mut().for_each(|p| *p = -1);
    }
    pub fn root(&self, mut x: usize) -> usize {
        assert!(x < self.p.len());
        while self.p[x] >= 0 {
            x = self.p[x] as usize;
        }
        x
    }
    pub fn same(&self, x: usize, y: usize) -> bool {
        assert!(x < self.p.len() && y < self.p.len());
        self.root(x) == self.root(y)
    }
    pub fn unite(&mut self, x: usize, y: usize) -> Option<(usize, usize)> {
        assert!(x < self.p.len() && y < self.p.len());
        let mut x = self.root(x);
        let mut y = self.root(y);
        if x == y {
            return None;
        }
        if self.p[x] > self.p[y] {
            std::mem::swap(&mut x, &mut y);
        }
        self.p[x] += self.p[y];
        self.p[y] = x as i32;
        Some((x, y))
    }
    pub fn parent(&self, x: usize) -> Option<usize> {
        assert!(x < self.p.len());
        let p = self.p[x];
        if p >= 0 {
            Some(p as usize)
        } else {
            None
        }
    }
    pub fn sum<F>(&self, mut x: usize, mut f: F) -> usize
    where
        F: FnMut(usize),
    {
        while let Some(p) = self.parent(x) {
            f(x);
            x = p;
        }
        x
    }
    pub fn size(&self, x: usize) -> usize {
        assert!(x < self.p.len());
        let r = self.root(x);
        (-self.p[r]) as usize
    }
}
//---------- end union_find ----------