#880186 (Rust) No.1983 [Cherry 4th Tune C] 南の島のマーメイド

• 問題: No.1983 [Cherry 4th Tune C] 南の島のマーメイド
• ユーザー: koba-e964
• 提出日時: 2023-06-13 00:15:37
• 言語: Rust (1.77.0 + proconio)
• 結果: AC
• 実行時間: 293 ms / 4,000 ms
• コード長: 6,755 bytes
• コンパイル時間: 18,386 ms
• コンパイル使用メモリ: 399,968 KB
• 実行使用メモリ: 106,824 KB
• 最終ジャッジ日時: 2024-06-11 23:44:07
• 合計ジャッジ時間: 26,856 ms
• ジャッジサーバーID （参考情報）: judge4 / judge1

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	1 ms; 6,812 KB
testcase_01	AC	1 ms; 6,816 KB
testcase_02	AC	1 ms; 6,812 KB
testcase_03	AC	1 ms; 6,940 KB
testcase_04	AC	1 ms; 6,944 KB
testcase_05	AC	1 ms; 6,940 KB
testcase_06	AC	1 ms; 6,944 KB
testcase_07	AC	1 ms; 6,944 KB
testcase_08	AC	4 ms; 6,940 KB
testcase_09	AC	6 ms; 6,940 KB
testcase_10	AC	9 ms; 6,940 KB
testcase_11	AC	9 ms; 6,940 KB
testcase_12	AC	5 ms; 6,944 KB
testcase_13	AC	125 ms; 31,468 KB
testcase_14	AC	161 ms; 35,676 KB
testcase_15	AC	191 ms; 45,052 KB
testcase_16	AC	65 ms; 28,260 KB
testcase_17	AC	164 ms; 36,164 KB
testcase_18	AC	187 ms; 44,544 KB
testcase_19	AC	250 ms; 53,364 KB
testcase_20	AC	177 ms; 42,148 KB
testcase_21	AC	202 ms; 40,872 KB
testcase_22	AC	221 ms; 43,776 KB
testcase_23	AC	275 ms; 57,268 KB
testcase_24	AC	279 ms; 57,260 KB
testcase_25	AC	293 ms; 58,136 KB
testcase_26	AC	271 ms; 58,060 KB
testcase_27	AC	282 ms; 57,324 KB
testcase_28	AC	276 ms; 57,200 KB
testcase_29	AC	257 ms; 57,216 KB
testcase_30	AC	284 ms; 58,684 KB
testcase_31	AC	264 ms; 57,640 KB
testcase_32	AC	269 ms; 58,304 KB
testcase_33	AC	1 ms; 6,944 KB
testcase_34	AC	58 ms; 27,064 KB
testcase_35	AC	132 ms; 78,600 KB
testcase_36	AC	113 ms; 42,292 KB
testcase_37	AC	1 ms; 6,940 KB
testcase_38	AC	31 ms; 6,940 KB
testcase_39	AC	183 ms; 106,824 KB
testcase_40	AC	126 ms; 56,832 KB

ソースコード

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, usize1) => (read_value!($next, usize) - 1);
    ($next:expr, $t:ty) => ($next().parse::<$t>().expect("Parse error"));
}

// Verified by: https://codeforces.com/contest/700/submission/165850980
// This function uses O(n) stack space.
mod tecomp {
    use std::cmp::min;
    const INF: usize = 1 << 28;
    fn dfs<EIdx: Copy + PartialEq>(v: usize, paridx: EIdx, g: &[Vec<(usize, EIdx)>],
           ord: &mut [usize], low: &mut [usize], k: &mut usize,
           bridges: &mut Vec<EIdx>) {
        ord[v] = *k;
        low[v] = *k;
        *k += 1;
        for &(w, eidx) in g[v].iter() {
            if paridx == eidx { continue; }
            if ord[w] < ord[v] {
                low[v] = min(low[v], ord[w]);
            } else if ord[w] == INF {
                dfs(w, eidx, g, ord, low, k, bridges);
                low[v] = min(low[v], low[w]);
                if ord[v] < low[w] {
                    bridges.push(eidx);
                }
            }
        }
    }
    fn dfs_comp<EIdx: Copy>(
        v: usize, g: &[Vec<(usize, EIdx)>],
        ord: &[usize], low: &[usize],
        cur_becomp: usize, becomp_count: &mut usize, becomp: &mut [usize], tree: &mut [Vec<(usize, EIdx)>],
        vis: &mut [bool],
    ) {
        becomp[v] = cur_becomp;
        vis[v] = true;
        for &(w, eidx) in g[v].iter() {
            if ord[w] > ord[v] && !vis[w] {
                if ord[v] < low[w] {
                    *becomp_count += 1;
                    tree[cur_becomp].push((*becomp_count, eidx));
                    dfs_comp(w, g, ord, low, *becomp_count, becomp_count, becomp, tree, vis);
                } else {
                    dfs_comp(w, g, ord, low, cur_becomp, becomp_count, becomp, tree, vis);
                }
            }
        }
    }

    type EIdx = usize;

    // Returns (the number of 2-edge connected components, [the id of the component v belongs to | v <- [0 .. g.len()]], the resulting tree, the ids of bridges).
    // Graphs are given and provided in the adjacent list format. (to, edge_id).
    // The provided tree has its own vertex ids, but edge ids are reused.
    // This function uses O(n) stack space.
    pub fn decomp(g: &[Vec<(usize, EIdx)>])
                 -> (usize, Vec<usize>, Vec<Vec<(usize, EIdx)>>, Vec<EIdx>) {
        let n_vert = g.len();
        let mut ord = vec![INF; n_vert];
        let mut low = vec![INF; n_vert];
        let mut k = 0;
        let mut becomp_count = 0;
        let mut becomp = vec![INF; n_vert];
        let mut bridges = Vec::new();
        // rooted forest
        let mut tree = vec![Vec::new(); n_vert];
        let mut vis = vec![false; n_vert];
        for i in 0 .. n_vert {
            if !vis[i] {
                dfs(i, !0, &g, &mut ord, &mut low, &mut k, &mut bridges);
                dfs_comp(i, &g, &ord, &low,
                         becomp_count, &mut becomp_count, &mut becomp,
                         &mut tree, &mut vis);
                becomp_count += 1;
            }
        }
        tree = tree[..becomp_count].to_vec();
        (becomp_count, becomp, tree, bridges)
    }
} // mod tecomp

// Union-Find tree.
// Verified by https://atcoder.jp/contests/pakencamp-2019-day3/submissions/9253305
struct UnionFind { disj: Vec<usize>, rank: Vec<usize> }

impl UnionFind {
    fn new(n: usize) -> Self {
        let disj = (0..n).collect();
        UnionFind { disj: disj, rank: vec![1; n] }
    }
    fn root(&mut self, x: usize) -> usize {
        if x != self.disj[x] {
            let par = self.disj[x];
            let r = self.root(par);
            self.disj[x] = r;
        }
        self.disj[x]
    }
    fn unite(&mut self, x: usize, y: usize) {
        let mut x = self.root(x);
        let mut y = self.root(y);
        if x == y { return }
        if self.rank[x] > self.rank[y] {
            std::mem::swap(&mut x, &mut y);
        }
        self.disj[x] = y;
        self.rank[y] += self.rank[x];
    }
    #[allow(unused)]
    fn is_same_set(&mut self, x: usize, y: usize) -> bool {
        self.root(x) == self.root(y)
    }
    #[allow(unused)]
    fn size(&mut self, x: usize) -> usize {
        let x = self.root(x);
        self.rank[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();
}

// https://yukicoder.me/problems/no/1983 (3.5)
// 関節点と橋を求め、橋だけで関節点・次数 1 の頂点すべてを繋いだときに同じ連結成分に属しているかどうか。
// パスが一意 => 構成する辺は全て橋: 橋以外が含まれているとそれを除去した時連結なので別のパスが取れる。
// パスが一意 => 通過する頂点はすべて関節点 or 次数 1: => そうでないとそれを除去した時、連結なままなので別のパスが取れる。
// 橋の両端は関節点 or 次数 1 であるため、後者の条件はいらないはず。
fn solve() {
    let out = std::io::stdout();
    let mut out = BufWriter::new(out.lock());
    macro_rules! puts {($($format:tt)*) => (let _ = write!(out,$($format)*););}
    input! {
        n: usize, m: usize, q: usize,
        uv: [(usize1, usize1); m],
        xy: [(usize1, usize1); q],
    }
    let mut uf = UnionFind::new(n);
    let mut g = vec![vec![]; n];
    for i in 0..m {
        let (u, v) = uv[i];
        g[u].push((v, i));
        g[v].push((u, i));
    }
    let (_, _, _, bridges) = tecomp::decomp(&g);
    for &idx in &bridges {
        let (u, v) = uv[idx];
        uf.unite(u, v);
    }
    for (x, y) in xy {
        puts!("{}\n", if uf.is_same_set(x, y) { "Yes" } else { "No" });
    }
}