#1146954 (Rust) No.3441 Sort Permutation 2

• 問題: No.3441 Sort Permutation 2
• ユーザー: akakimidori
• 提出日時: 2026-02-06 21:29:11
• 言語: Rust (1.92.0 + proconio + num + itertools)
• 結果: AC
• 実行時間: 37 ms / 2,000 ms
• コード長: 5,171 bytes
• コンパイル時間: 18,158 ms
• コンパイル使用メモリ: 212,640 KB
• 実行使用メモリ: 7,972 KB
• 最終ジャッジ日時: 2026-02-06 21:29:39
• 合計ジャッジ時間: 8,869 ms
• ジャッジサーバーID （参考情報）: judge4 / judge2

ファイルパターン	結果
sample	AC * 3
other	AC * 41

ソースコード

fn main() {
    input! {
        n: usize,
        p: [usize1; n],
    }
    let mut dp = vec![0; n + 1];
    let mut used = vec![false; n];
    for i in 0..n {
        if used[i] {
            continue;
        }
        let mut pos = i;
        let mut g = 0;
        let mut len = 0;
        while !used[pos] {
            g = gcd(g, pos - i);
            used[pos] = true;
            pos = p[pos];
            len += 1;
        }
        dp[g] += len - 1
    }
    enumerate_prime(n, |p| {
        for j in (1..=(n / p)).rev() {
            dp[j] += dp[j * p];
        }
    });
    use util::*;
    println!("{}", dp[1..n].iter().join("\n"));
}

fn gcd(a: usize, b: usize) -> usize {
    if b == 0 {
        a
    } else {
        gcd(b, a % b)
    }
}

// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
#[macro_export]
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_export]
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_export]
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 ----------
// --------- end sieve ----------
pub struct Sieve {
    size: usize,
    factor: Vec<usize>,
}

impl Sieve {
    pub fn new(size: usize) -> Sieve {
        let mut factor = (0..(size + 1)).collect::<Vec<_>>();
        for i in (2..).take_while(|p| p * p <= size) {
            if i == factor[i] {
                for j in i..(size / i + 1) {
                    factor[j * i] = i;
                }
            }
        }
        Sieve {
            size: size,
            factor: factor,
        }
    }
    pub fn factor(&self, n: usize) -> Option<usize> {
        assert!(n <= self.size);
        if n == 1 {
            None
        } else {
            Some(self.factor[n])
        }
    }
    pub fn factorize(&self, mut n: usize, res: &mut Vec<usize>) {
        assert!(n <= self.size);
        res.clear();
        res.push(1);
        while let Some(p) = self.factor(n) {
            let len = res.len();
            while n % p == 0 {
                n /= p;
                for _ in 0..len {
                    let v = res[res.len() - len] * p;
                    res.push(v);
                }
            }
        }
    }
}
// --------- end sieve ----------
// ---------- begin enumerate prime ----------
fn enumerate_prime<F>(n: usize, mut f: F)
where
    F: FnMut(usize),
{
    assert!(1 <= n && n <= 5 * 10usize.pow(8));
    let batch = (n as f64).sqrt().ceil() as usize;
    let mut is_prime = vec![true; batch + 1];
    for i in (2..).take_while(|p| p * p <= batch) {
        if is_prime[i] {
            let mut j = i * i;
            while let Some(p) = is_prime.get_mut(j) {
                *p = false;
                j += i;
            }
        }
    }
    let mut prime = vec![];
    for (i, p) in is_prime.iter().enumerate().skip(2) {
        if *p && i <= n {
            f(i);
            prime.push(i);
        }
    }
    let mut l = batch + 1;
    while l <= n {
        let r = std::cmp::min(l + batch, n + 1);
        is_prime.clear();
        is_prime.resize(r - l, true);
        for &p in prime.iter() {
            let mut j = (l + p - 1) / p * p - l;
            while let Some(is_prime) = is_prime.get_mut(j) {
                *is_prime = false;
                j += p;
            }
        }
        for (i, _) in is_prime.iter().enumerate().filter(|p| *p.1) {
            f(i + l);
        }
        l += batch;
    }
}
// ---------- end enumerate prime ----------
mod util {
    pub trait Join {
        fn join(self, sep: &str) -> String;
    }

    impl<T, I> Join for I
    where
        I: Iterator<Item = T>,
        T: std::fmt::Display,
    {
        fn join(self, sep: &str) -> String {
            let mut s = String::new();
            use std::fmt::*;
            for (i, v) in self.enumerate() {
                if i > 0 {
                    write!(&mut s, "{}", sep).ok();
                }
                write!(&mut s, "{}", v).ok();
            }
            s
        }
    }
}