結果

問題 No.1553 Lovely City
ユーザー akakimidoriakakimidori
提出日時 2021-06-18 23:08:34
言語 Rust
(1.77.0 + proconio)
結果
AC  
実行時間 172 ms / 2,000 ms
コード長 5,060 bytes
コンパイル時間 12,259 ms
コンパイル使用メモリ 378,708 KB
実行使用メモリ 32,316 KB
最終ジャッジ日時 2024-06-22 21:20:58
合計ジャッジ時間 19,157 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge5
このコードへのチャレンジ
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テストケース

テストケース表示
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 8 ms
7,272 KB
testcase_03 AC 1 ms
5,376 KB
testcase_04 AC 1 ms
5,376 KB
testcase_05 AC 1 ms
5,376 KB
testcase_06 AC 1 ms
5,376 KB
testcase_07 AC 1 ms
5,376 KB
testcase_08 AC 110 ms
21,084 KB
testcase_09 AC 120 ms
22,604 KB
testcase_10 AC 115 ms
22,732 KB
testcase_11 AC 87 ms
18,936 KB
testcase_12 AC 109 ms
22,676 KB
testcase_13 AC 101 ms
19,412 KB
testcase_14 AC 109 ms
21,096 KB
testcase_15 AC 93 ms
20,360 KB
testcase_16 AC 126 ms
23,664 KB
testcase_17 AC 80 ms
18,624 KB
testcase_18 AC 159 ms
32,148 KB
testcase_19 AC 164 ms
31,924 KB
testcase_20 AC 160 ms
31,868 KB
testcase_21 AC 166 ms
32,136 KB
testcase_22 AC 166 ms
32,160 KB
testcase_23 AC 159 ms
32,044 KB
testcase_24 AC 167 ms
32,232 KB
testcase_25 AC 169 ms
32,008 KB
testcase_26 AC 166 ms
32,304 KB
testcase_27 AC 172 ms
32,316 KB
権限があれば一括ダウンロードができます

ソースコード

diff # 

//---------- 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 ----------
// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};
    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, bytes) => {
        read_value!($iter, String).bytes().collect::<Vec<u8>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}
// ---------- end input macro ----------

fn run() {
    input! {
        n: usize,
        m: usize,
        cond: [(usize1, usize1); m],
    }
    let mut dsu = DSU::new(n);
    let mut edge = vec![vec![]; n];
    for (a, b) in cond {
        if let Some((x, y)) = dsu.unite(a, b) {
            let mut p = std::mem::take(&mut edge[y]);
            edge[x].append(&mut p);
        }
        edge[dsu.root(a)].push((a, b));
    }
    let mut ans = vec![];
    for i in 0..n {
        if i != dsu.root(i) {
            continue;
        }
        let edge = std::mem::take(&mut edge[i]);
        let mut z = vec![];
        z.extend(edge.iter().map(|e| e.0));
        z.extend(edge.iter().map(|e| e.1));
        z.sort();
        z.dedup();
        let n = z.len();
        let mut g = vec![vec![]; n];
        let mut deg = vec![0; n];
        for &(a, b) in edge.iter() {
            let a = z.binary_search(&a).unwrap();
            let b = z.binary_search(&b).unwrap();
            deg[b] += 1;
            g[a].push(b);
        }
        let mut topo = vec![];
        for i in 0..n {
            if deg[i] == 0 {
                topo.push(i);
            }
        }
        for i in 0..n {
            if i >= topo.len() {
                break;
            }
            let v = topo[i];
            for &u in g[v].iter() {
                deg[u] -= 1;
                if deg[u] == 0 {
                    topo.push(u);
                }
            }
        }
        if topo.len() == n {
            for e in topo.windows(2) {
                ans.push((z[e[0]], z[e[1]]));
            }
        } else {
            let f = z[0];
            z.push(f);
            for z in z.windows(2) {
                ans.push((z[0], z[1]));
            }
        }
    }
    use std::io::Write;
    let out = std::io::stdout();
    let mut out = std::io::BufWriter::new(out.lock());
    writeln!(out, "{}", ans.len()).ok();
    for a in ans {
        writeln!(out, "{} {}", a.0 + 1, a.1 + 1).ok();
    }
}

fn main() {
    run();
}
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