#1147166 (Rust) No.3442 Good Vertex Connectivity

• 問題: No.3442 Good Vertex Connectivity
• ユーザー: akakimidori
• 提出日時: 2026-02-07 01:03:11
• 言語: Rust (1.92.0 + proconio + num + itertools)
• 結果: AC
• 実行時間: 1,060 ms / 3,000 ms
• コード長: 13,680 bytes
• コンパイル時間: 2,255 ms
• コンパイル使用メモリ: 226,344 KB
• 実行使用メモリ: 47,036 KB
• 最終ジャッジ日時: 2026-02-07 01:03:59
• 合計ジャッジ時間: 44,812 ms
• ジャッジサーバーID （参考情報）: judge2 / judge1

ファイルパターン	結果
sample	AC * 1
other	AC * 69

コンパイルメッセージ

warning: unused import: `std::collections::*`
   --> src/main.rs:113:5
    |
113 | use std::collections::*;
    |     ^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default

ソースコード

fn run<W: Write>(sc: &mut scanner::Scanner, out: &mut std::io::BufWriter<W>) {
    let n: usize = sc.next();
    let mut hld = HLD::new(n);
    let root = 0;
    for _ in 1..n {
        let a = sc.next::<usize>() - 1;
        let b = sc.next::<usize>() - 1;
        hld.add_edge(a, b);
    }
    hld.build(root);
    let mut depth = vec![0; n];
    for i in 0..n {
        let v = hld.vertex(i);
        for &u in hld.child[v].iter() {
            depth[u] = depth[v] + 1;
        }
    }
    let dist = |a: usize, b: usize| -> u32 { depth[a] + depth[b] - 2 * depth[hld.lca(a, b)] };
    let mut c = vec![0; n];
    type T = (u32, u32, u32);
    let merge = |a: &T, b: &T| -> T {
        if a.0 == (n as u32) {
            return *b;
        }
        if b.0 == (n as u32) {
            return *a;
        }
        let d = a.2 + b.2 + dist(a.1 as usize, b.0 as usize);
        (a.0, b.1, d)
    };
    let empty = (n as u32, n as u32, 0);
    let mut seg = SegmentTreePURQ::new(2 * n, empty, merge);
    for i in 0..n {
        c[i] = sc.next::<u32>();
        if c[i] == 1 {
            let x = hld.sub_tree(i).0;
            let p = (i as u32, i as u32, 0);
            seg.update_tmp(x, p);
            seg.update_tmp(x + n, p);
        }
    }
    seg.update_all();
    let q = sc.next::<u32>();
    for _ in 0..q {
        let op = sc.next::<u8>();
        if op == 1 {
            let v = sc.next::<usize>() - 1;
            let x = hld.sub_tree(v).0;
            if c[v] == 1 {
                seg.update(x, empty);
                seg.update(x + n, empty);
            } else {
                let p = (v as u32, v as u32, 0);
                seg.update(x, p);
                seg.update(x + n, p);
            }
            c[v] ^= 1;
        } else {
            let x = sc.next::<usize>() - 1;
            let y = sc.next::<usize>() - 1;
            let p = hld.sub_tree(x);
            let q = hld.sub_tree(y);
            let to_ans = |v: T| -> u32 {
                if v.0 == (n as u32) {
                    0
                } else {
                    (v.2 + dist(v.0 as usize, v.1 as usize)) / 2 + 1
                }
            };
            let ans = to_ans(if x == y {
                seg.find(0, n)
            } else if q.0 <= p.0 && p.1 <= q.1 {
                let z = hld.next(y, x);
                let (l, r) = hld.sub_tree(z);
                seg.find(r, n + l)
            } else {
                seg.find(q.0, q.1)
            });
            writeln!(out, "{}", ans).ok();
        }
    }
}

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

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 Heavy-Light decomposition ----------
pub struct HLD {
    size: usize,
    edge: Vec<(usize, usize)>,
    child: Vec<Vec<usize>>,
    path_root: Vec<usize>,
    parent: Vec<usize>,
    left: Vec<usize>,
    right: Vec<usize>,
    inverse: Vec<usize>,
}

impl HLD {
    pub fn new(size: usize) -> Self {
        assert!(size <= 10usize.pow(8));
        HLD {
            size: size,
            edge: Vec::with_capacity(size - 1),
            child: Vec::new(),
            path_root: Vec::new(),
            parent: Vec::new(),
            left: Vec::new(),
            right: Vec::new(),
            inverse: Vec::new(),
        }
    }
    pub fn add_edge(&mut self, a: usize, b: usize) {
        assert!(a != b && a < self.size && b < self.size);
        self.edge.push((a, b));
    }
    pub fn build(&mut self, root: usize) {
        assert!(self.edge.len() + 1 == self.size);
        let size = self.size;
        let mut cnt = vec![0; size];
        for &(a, b) in self.edge.iter() {
            cnt[a] += 1;
            cnt[b] += 1;
        }
        let mut child = cnt
            .into_iter()
            .map(|c| Vec::with_capacity(c))
            .collect::<Vec<_>>();
        for &(a, b) in self.edge.iter() {
            child[a].push(b);
            child[b].push(a);
        }
        let mut parent = vec![size; size];
        let mut q = Vec::with_capacity(size);
        q.push(root);
        parent[root] = root;
        for i in 0..size {
            let v = q[i];
            for u in child[v].clone() {
                assert!(parent[u] == size);
                parent[u] = v;
                child[u].retain(|e| *e != v);
                q.push(u);
            }
        }
        let mut sum = vec![1; size];
        for &v in q.iter().rev() {
            let child = &mut child[v];
            if !child.is_empty() {
                let (pos, _) = child.iter().enumerate().max_by_key(|p| sum[*p.1]).unwrap();
                child.swap(0, pos);
                sum[v] = 1 + child.iter().fold(0, |s, a| s + sum[*a]);
            }
        }
        let mut path_root = (0..size).collect::<Vec<_>>();
        let mut left = vec![0; size];
        let mut right = vec![0; size];
        let mut dfs = vec![(root, false)];
        let mut id = 0;
        while let Some((v, end)) = dfs.pop() {
            if end {
                right[v] = id;
                continue;
            }
            left[v] = id;
            id += 1;
            dfs.push((v, true));
            let child = &child[v];
            if !child.is_empty() {
                for &u in child[1..].iter() {
                    path_root[u] = u;
                    dfs.push((u, false));
                }
                let u = child[0];
                path_root[u] = path_root[v];
                dfs.push((u, false));
            }
        }
        let mut inverse = vec![size; size];
        for (i, l) in left.iter().enumerate() {
            inverse[*l] = i;
        }
        self.child = child;
        self.parent = parent;
        self.left = left;
        self.right = right;
        self.path_root = path_root;
        self.inverse = inverse;
    }
    pub fn lca(&self, mut a: usize, mut b: usize) -> usize {
        assert!(a < self.size && b < self.size);
        let path = &self.path_root;
        let parent = &self.parent;
        let index = &self.left;
        while path[a] != path[b] {
            if index[a] > index[b] {
                std::mem::swap(&mut a, &mut b);
            }
            b = parent[path[b]];
        }
        std::cmp::min((index[a], a), (index[b], b)).1
    }
    pub fn path(
        &self,
        src: usize,
        dst: usize,
        up: &mut Vec<(usize, usize)>,
        down: &mut Vec<(usize, usize)>,
    ) {
        assert!(src < self.size && dst < self.size);
        up.clear();
        down.clear();
        let path = &self.path_root;
        let parent = &self.parent;
        let index = &self.left;
        let mut x = src;
        let mut y = dst;
        while path[x] != path[y] {
            if index[x] > index[y] {
                let p = path[x];
                assert!(p == path[p]);
                up.push((index[p], index[x] + 1));
                x = parent[p];
            } else {
                let p = path[y];
                assert!(p == path[p]);
                down.push((index[p], index[y] + 1));
                y = parent[p];
            }
        }
        if index[x] <= index[y] {
            down.push((index[x], index[y] + 1));
        } else {
            up.push((index[y], index[x] + 1));
        }
        down.reverse();
    }
    pub fn sub_tree(&self, v: usize) -> (usize, usize) {
        assert!(v < self.size);
        (self.left[v], self.right[v])
    }
    pub fn parent(&self, v: usize) -> Option<usize> {
        assert!(v < self.size);
        let p = self.parent[v];
        if p == v {
            None
        } else {
            Some(p)
        }
    }
    // s -> t へのパスの2番目の頂点を返す
    pub fn next(&self, s: usize, t: usize) -> usize {
        assert!(s < self.size && t < self.size && s != t);
        let (a, b) = self.sub_tree(s);
        let (c, d) = self.sub_tree(t);
        if !(a <= c && d <= b) {
            return self.parent[s];
        }
        let mut pos = t;
        let mut pre = t;
        while self.path_root[s] != self.path_root[pos] {
            pre = self.path_root[pos];
            pos = self.parent[pre];
        }
        if s == pos {
            pre
        } else {
            self.child[s][0]
        }
    }
    pub fn vertex(&self, x: usize) -> usize {
        assert!(x < self.size);
        self.inverse[x]
    }
    pub fn jump(
        &self,
        s: usize,
        t: usize,
        mut k: usize,
        up: &mut Vec<(usize, usize)>,
        down: &mut Vec<(usize, usize)>,
    ) -> Option<usize> {
        assert!(s.max(t) < self.size);
        self.path(s, t, up, down);
        for (l, r) in up.drain(..) {
            if k < r - l {
                return Some(self.vertex(r - 1 - k));
            }
            k -= r - l;
        }
        for (l, r) in down.drain(..) {
            if k < r - l {
                return Some(self.vertex(l + k));
            }
            k -= r - l;
        }
        None
    }
}
// ---------- end Heavy-Light decomposition ----------

// ---------- begin segment tree Point Update Range Query ----------
pub struct SegmentTreePURQ<T, F> {
    n: usize,
    size: usize,
    data: Vec<T>,
    e: T,
    op: F,
}

impl<T, F> SegmentTreePURQ<T, F>
where
    T: Clone,
    F: Fn(&T, &T) -> T,
{
    pub fn new(n: usize, e: T, op: F) -> Self {
        assert!(n > 0);
        let size = n.next_power_of_two();
        let data = vec![e.clone(); 2 * size];
        SegmentTreePURQ {
            n,
            size,
            data,
            e,
            op,
        }
    }
    pub fn update_tmp(&mut self, x: usize, v: T) {
        assert!(x < self.n);
        self.data[x + self.size] = v;
    }
    pub fn update_all(&mut self) {
        for i in (1..self.size).rev() {
            self.data[i] = (self.op)(&self.data[2 * i], &self.data[2 * i + 1]);
        }
    }
    pub fn update(&mut self, x: usize, v: T) {
        assert!(x < self.n);
        let mut x = x + self.size;
        self.data[x] = v;
        x >>= 1;
        while x > 0 {
            self.data[x] = (self.op)(&self.data[2 * x], &self.data[2 * x + 1]);
            x >>= 1;
        }
    }
    pub fn find(&self, l: usize, r: usize) -> T {
        assert!(l <= r && r <= self.n);
        if l == r {
            return self.e.clone();
        }
        let mut l = self.size + l;
        let mut r = self.size + r;
        let mut x = self.e.clone();
        let mut y = self.e.clone();
        while l < r {
            if l & 1 == 1 {
                x = (self.op)(&x, &self.data[l]);
                l += 1;
            }
            if r & 1 == 1 {
                r -= 1;
                y = (self.op)(&self.data[r], &y);
            }
            l >>= 1;
            r >>= 1;
        }
        (self.op)(&x, &y)
    }
    pub fn max_right<P>(&self, l: usize, f: P) -> usize
    where
        P: Fn(&T) -> bool,
    {
        assert!(l <= self.n);
        assert!(f(&self.e));
        if l == self.n {
            return self.n;
        }
        let mut l = l + self.size;
        let mut sum = self.e.clone();
        while {
            l >>= l.trailing_zeros();
            let v = (self.op)(&sum, &self.data[l]);
            if !f(&v) {
                while l < self.size {
                    l <<= 1;
                    let v = (self.op)(&sum, &self.data[l]);
                    if f(&v) {
                        sum = v;
                        l += 1;
                    }
                }
                return l - self.size;
            }
            sum = v;
            l += 1;
            l.count_ones() > 1
        } {}
        self.n
    }
    pub fn min_left<P>(&self, r: usize, f: P) -> usize
    where
        P: Fn(&T) -> bool,
    {
        assert!(r <= self.n);
        assert!(f(&self.e));
        if r == 0 {
            return 0;
        }
        let mut r = r + self.size;
        let mut sum = self.e.clone();
        while {
            r -= 1;
            while r > 1 && r & 1 == 1 {
                r >>= 1;
            }
            let v = (self.op)(&self.data[r], &sum);
            if !f(&v) {
                while r < self.size {
                    r = 2 * r + 1;
                    let v = (self.op)(&self.data[r], &sum);
                    if f(&v) {
                        sum = v;
                        r -= 1;
                    }
                }
                return r + 1 - self.size;
            }
            sum = v;
            (r & (!r + 1)) != r
        } {}
        0
    }
}
// ---------- end segment tree Point Update Range Query ----------