#935672 (Rust) No.2563 色ごとのグループ

• 問題: No.2563 色ごとのグループ
• ユーザー: naut3
• 提出日時: 2023-12-02 20:28:37
• 言語: Rust (1.77.0 + proconio)
• 結果: AC
• 実行時間: 59 ms / 2,000 ms
• コード長: 4,465 bytes
• コンパイル時間: 14,314 ms
• コンパイル使用メモリ: 377,852 KB
• 実行使用メモリ: 11,136 KB
• 最終ジャッジ日時: 2024-09-26 21:38:34
• 合計ジャッジ時間: 14,131 ms
• ジャッジサーバーID （参考情報）: judge2 / judge5

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	1 ms; 5,248 KB
testcase_01	AC	1 ms; 5,248 KB
testcase_02	AC	1 ms; 5,248 KB
testcase_03	AC	1 ms; 5,248 KB
testcase_04	AC	1 ms; 5,248 KB
testcase_05	AC	1 ms; 5,248 KB
testcase_06	AC	1 ms; 5,376 KB
testcase_07	AC	1 ms; 5,376 KB
testcase_08	AC	1 ms; 5,376 KB
testcase_09	AC	1 ms; 5,376 KB
testcase_10	AC	1 ms; 5,376 KB
testcase_11	AC	1 ms; 5,376 KB
testcase_12	AC	1 ms; 5,376 KB
testcase_13	AC	1 ms; 5,376 KB
testcase_14	AC	1 ms; 5,376 KB
testcase_15	AC	1 ms; 5,376 KB
testcase_16	AC	1 ms; 5,376 KB
testcase_17	AC	1 ms; 5,376 KB
testcase_18	AC	1 ms; 5,376 KB
testcase_19	AC	1 ms; 5,376 KB
testcase_20	AC	3 ms; 5,376 KB
testcase_21	AC	2 ms; 5,376 KB
testcase_22	AC	2 ms; 5,376 KB
testcase_23	AC	2 ms; 5,376 KB
testcase_24	AC	20 ms; 5,504 KB
testcase_25	AC	17 ms; 6,016 KB
testcase_26	AC	27 ms; 8,064 KB
testcase_27	AC	27 ms; 10,624 KB
testcase_28	AC	31 ms; 8,704 KB
testcase_29	AC	45 ms; 11,008 KB
testcase_30	AC	45 ms; 11,008 KB
testcase_31	AC	43 ms; 11,008 KB
testcase_32	AC	44 ms; 11,008 KB
testcase_33	AC	59 ms; 11,136 KB
testcase_34	AC	56 ms; 11,008 KB
testcase_35	AC	57 ms; 11,008 KB
testcase_36	AC	57 ms; 11,136 KB
testcase_37	AC	56 ms; 11,136 KB

ソースコード

#![allow(non_snake_case, unused_imports, unused_must_use)]
use std::io::{self, prelude::*};
use std::str;

fn main() {
    let (stdin, stdout) = (io::stdin(), io::stdout());
    let mut scan = Scanner::new(stdin.lock());
    let mut out = io::BufWriter::new(stdout.lock());

    macro_rules! input {
        ($T: ty) => {
            scan.token::<$T>()
        };
        ($T: ty, $N: expr) => {
            (0..$N).map(|_| scan.token::<$T>()).collect::<Vec<_>>()
        };
    }

    let N = input!(usize);
    let M = input!(usize);

    let C = input!(usize, N);

    let mut uf = UnionFind::new(N);

    let mut roots = vec![1 << 30; N + 1];

    for i in 0..N {
        if roots[C[i]] == 1 << 30 {
            roots[C[i]] = i;
        }
    }

    for _ in 0..M {
        let (u, v) = (input!(usize) - 1, input!(usize) - 1);

        if C[u] == C[v] {
            uf.unite(u, v);
        }
    }

    let mut ans = 0_usize;

    for i in 0..N {
        if !uf.issame(roots[C[i]], i) {
            uf.unite(roots[C[i]], i);
            ans += 1;
        }
    }

    writeln!(out, "{}", ans);
}

#[derive(Clone)]
pub struct UnionFind {
    size: usize,
    par: Vec<usize>,
    rank: Vec<usize>,
    cnt: Vec<usize>,
}

impl UnionFind {
    /// self = {0}, {1}, ..., {size - 1}
    pub fn new(size: usize) -> Self {
        return Self {
            size: size,
            par: vec![size; size],
            rank: vec![0; size],
            cnt: vec![1; size],
        };
    }

    /// check whether set s1 (∋ a) and set s2 (∋ b) are equal
    pub fn issame(&mut self, a: usize, b: usize) -> bool {
        assert!(a < self.size && b < self.size);
        return self.root(a) == self.root(b);
    }

    /// unite set s1 (∋ a) and set s2 (∋ b)
    pub fn unite(&mut self, mut a: usize, mut b: usize) {
        a = self.root(a);
        b = self.root(b);

        if a != b {
            if self.rank[a] < self.rank[b] {
                std::mem::swap(&mut a, &mut b);
            }
            self.par[b] = a;

            if self.rank[a] == self.rank[b] {
                self.rank[a] += 1;
            }

            self.cnt[a] += self.cnt[b];
        }
    }

    /// get the size of set s1 (∋ a)
    pub fn size(&mut self, x: usize) -> usize {
        let r = self.root(x);
        return self.cnt[r];
    }

    fn root(&mut self, x: usize) -> usize {
        if self.par[x] == self.size {
            return x;
        } else {
            self.par[x] = self.root(self.par[x]);
            return self.par[x];
        }
    }
}

impl std::fmt::Display for UnionFind {
    #[allow(unused_must_use)]
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        let mut uf = self.clone();
        let roots = (0..uf.size).map(|i| uf.root(i)).collect::<Vec<_>>();

        let set = {
            let mut s = std::collections::BTreeSet::new();
            for &r in roots.iter() {
                s.insert(r);
            }
            s
        };

        let cc = {
            let mut m = std::collections::BTreeMap::new();
            for (i, &r) in set.iter().enumerate() {
                m.insert(r, i);
            }
            m
        };

        let mut ret = vec![vec![]; cc.len()];

        for i in 0..uf.size {
            ret[*cc.get(&roots[i]).unwrap()].push(i);
        }

        for r in ret {
            write!(
                f,
                "{{{}}} ",
                r.iter()
                    .map(|x| x.to_string())
                    .collect::<Vec<_>>()
                    .join(" ")
            );
        }

        return Ok(());
    }
}

struct Scanner<R> {
    reader: R,
    buf_str: Vec<u8>,
    buf_iter: str::SplitWhitespace<'static>,
}
impl<R: BufRead> Scanner<R> {
    fn new(reader: R) -> Self {
        Self {
            reader,
            buf_str: vec![],
            buf_iter: "".split_whitespace(),
        }
    }
    fn token<T: str::FromStr>(&mut self) -> T {
        loop {
            if let Some(token) = self.buf_iter.next() {
                return token.parse().ok().expect("Failed parse");
            }
            self.buf_str.clear();
            self.reader
                .read_until(b'\n', &mut self.buf_str)
                .expect("Failed read");
            self.buf_iter = unsafe {
                let slice = str::from_utf8_unchecked(&self.buf_str);
                std::mem::transmute(slice.split_whitespace())
            }
        }
    }
}