#937563 (Rust) No.979 Longest Divisor Sequence

• 問題: No.979 Longest Divisor Sequence
• ユーザー: Yukino DX.
• 提出日時: 2023-12-08 23:31:17
• 言語: Rust (1.77.0 + proconio)
• 結果: AC
• 実行時間: 505 ms / 2,000 ms
• コード長: 4,238 bytes
• コンパイル時間: 18,933 ms
• コンパイル使用メモリ: 380,524 KB
• 実行使用メモリ: 9,728 KB
• 最終ジャッジ日時: 2024-09-27 03:16:54
• 合計ジャッジ時間: 17,354 ms
• ジャッジサーバーID （参考情報）: judge3 / 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	0 ms; 5,248 KB
testcase_03	AC	1 ms; 5,248 KB
testcase_04	AC	0 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	0 ms; 5,376 KB
testcase_09	AC	1 ms; 5,376 KB
testcase_10	AC	7 ms; 5,376 KB
testcase_11	AC	7 ms; 5,376 KB
testcase_12	AC	7 ms; 5,376 KB
testcase_13	AC	16 ms; 6,016 KB
testcase_14	AC	505 ms; 9,728 KB
testcase_15	AC	158 ms; 6,144 KB

ソースコード

#![allow(non_snake_case)]
#![allow(unused_imports)]
// use itertools::Itertools;
// use proconio::input;
// use proconio::marker::*;
use std::cmp::Reverse;
use std::collections::*;

fn main() {
    input! {
        n:usize,
        a:[usize;n],
    }

    let m = *a.iter().max().unwrap();
    let mut idxs = vec![n; m + 1];
    let mut dp = vec![1; n];
    for i in 0..n {
        let divs = divisors(a[i]);
        for div in divs {
            if idxs[div] == n {
                continue;
            }

            if div == a[i] {
                dp[i] = dp[i].max(dp[idxs[a[i]]]);
            } else {
                dp[i] = dp[i].max(dp[idxs[div]] + 1);
            }
        }

        idxs[a[i]] = i;
    }

    let ans = *dp.iter().max().unwrap();
    println!("{}", ans);
}

use math::*;
mod math {
    use std::collections::HashMap;

    #[allow(dead_code)]
    pub fn pow(mut n: usize, mut e: usize, m: usize) -> usize {
        let mut res = 1;
        while 0 < e {
            if e & 1 != 0 {
                res *= n;
                res %= m;
            }

            n *= n;
            n %= m;
            e >>= 1;
        }

        res
    }

    #[allow(dead_code)]
    pub fn gcd(a: usize, b: usize) -> usize {
        if b == 0 {
            a
        } else {
            gcd(b, a % b)
        }
    }

    #[allow(dead_code)]
    pub fn lcm(a: usize, b: usize) -> usize {
        a / gcd(a, b) * b
    }

    #[allow(dead_code)]
    pub fn prime_factor(mut n: usize) -> HashMap<usize, usize> {
        let mut pfacs = HashMap::new();
        for d in 2.. {
            if d * d > n {
                break;
            }

            while n % d == 0 {
                *pfacs.entry(d).or_insert(0) += 1;
                n /= d;
            }
        }
        if n != 1 {
            *pfacs.entry(n).or_insert(0) += 1;
        }

        pfacs
    }

    #[allow(dead_code)]
    pub fn divisors(n: usize) -> Vec<usize> {
        let mut divs = vec![];
        for d in (1..).take_while(|&d| d * d <= n) {
            if n % d == 0 {
                divs.push(d);
                if n / d != d {
                    divs.push(n / d);
                }
            }
        }

        divs
    }

    #[allow(dead_code)]
    pub fn eratosthenes_sieve(n: usize) -> Vec<usize> {
        let mut is_primes = vec![true; n + 1];
        is_primes[0] = false;
        is_primes[1] = false;
        let mut primes = vec![];

        for i in 2..=n {
            if !is_primes[i] {
                continue;
            }

            for j in (2 * i..=n).step_by(i) {
                is_primes[j] = false;
            }
        }

        for (val, is_prime) in is_primes.into_iter().enumerate() {
            if is_prime {
                primes.push(val);
            }
        }

        primes
    }
}

mod input {
    #[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>>()
        };

        ($iter:expr, usize1) => {
            read_value!($iter, usize) - 1
        };

        ($iter:expr, $t:ty) => {
            $iter.next().unwrap().parse::<$t>().expect("Parse error")
        };
    }
}