#693689 (Rust) No.1659 Product of Divisors

• 問題: No.1659 Product of Divisors
• ユーザー: fukafukatani
• 提出日時: 2021-08-28 15:21:40
• 言語: Rust (1.77.0)
• 結果: AC
• 実行時間: 7 ms / 2,000 ms
• コード長: 7,486 bytes
• コンパイル時間: 2,143 ms
• コンパイル使用メモリ: 166,456 KB
• 実行使用メモリ: 4,380 KB
• 最終ジャッジ日時: 2023-08-14 03:06:08
• 合計ジャッジ時間: 3,452 ms
• ジャッジサーバーID （参考情報）: judge15 / judge11

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	6 ms; 4,380 KB
testcase_01	AC	6 ms; 4,380 KB
testcase_02	AC	6 ms; 4,376 KB
testcase_03	AC	6 ms; 4,376 KB
testcase_04	AC	6 ms; 4,380 KB
testcase_05	AC	6 ms; 4,376 KB
testcase_06	AC	6 ms; 4,376 KB
testcase_07	AC	6 ms; 4,376 KB
testcase_08	AC	6 ms; 4,376 KB
testcase_09	AC	6 ms; 4,376 KB
testcase_10	AC	7 ms; 4,376 KB
testcase_11	AC	6 ms; 4,376 KB
testcase_12	AC	7 ms; 4,376 KB
testcase_13	AC	6 ms; 4,380 KB
testcase_14	AC	6 ms; 4,380 KB
testcase_15	AC	6 ms; 4,380 KB
testcase_16	AC	7 ms; 4,380 KB
testcase_17	AC	6 ms; 4,376 KB
testcase_18	AC	6 ms; 4,380 KB
testcase_19	AC	6 ms; 4,376 KB
testcase_20	AC	6 ms; 4,376 KB
testcase_21	AC	7 ms; 4,380 KB
testcase_22	AC	7 ms; 4,376 KB
testcase_23	AC	6 ms; 4,376 KB
testcase_24	AC	6 ms; 4,376 KB

コンパイルメッセージ

warning: function `mod_comb` is never used
   --> Main.rs:230:4
    |
230 | fn mod_comb(n: usize, k: usize, fact: &[Modulo], fact_inv: &[Modulo]) -> Modulo {
    |    ^^^^^^^^
    |
    = note: `#[warn(dead_code)]` on by default

warning: associated function `set_modulus` is never used
  --> Main.rs:53:8
   |
53 |     fn set_modulus(m: i64) {
   |        ^^^^^^^^^^^

warning: 2 warnings emitted

ソースコード

#![allow(unused_imports)]
use std::cmp::*;
use std::collections::*;
use std::io::Write;
use std::ops::Bound::*;

#[allow(unused_macros)]
macro_rules! debug {
    ($($e:expr),*) => {
        #[cfg(debug_assertions)]
        $({
            let (e, mut err) = (stringify!($e), std::io::stderr());
            writeln!(err, "{} = {:?}", e, $e).unwrap()
        })*
    };
}

fn main() {
    let v = read_vec::<i64>();
    let (n, k) = (v[0], v[1]);
    let primes = get_primes(1000000);

    let factor_counts = factorize(n, &primes).values().cloned().collect::<Vec<_>>();
    let mut ans = Modulo(1);
    for count in factor_counts {
        let mut temp = Modulo(1);
        for i in 0..count {
            temp *= Modulo::new(k + count - i);
            temp *= Modulo(i + 1).inv();
        }
        ans *= temp;
    }
    println!("{}", ans);
}

fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}

#[derive(Clone, Copy, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
struct Modulo(i64);
static mut MODULUS: i64 = 1000_000_000 + 7;
impl Modulo {
    fn set_modulus(m: i64) {
        unsafe {
            MODULUS = m;
        }
    }
    fn get_modulus() -> i64 {
        unsafe { MODULUS }
    }
    fn new(x: i64) -> Modulo {
        let m = Modulo::get_modulus();
        if x < 0 {
            Modulo(x % m + m)
        } else if x < m {
            Modulo(x)
        } else {
            Modulo(x % m)
        }
    }
    fn pow(self, p: i64) -> Modulo {
        if p == 0 {
            Modulo(1)
        } else {
            let mut t = self.pow(p / 2);
            t *= t;
            if p & 1 == 1 {
                t *= self;
            }
            t
        }
    }
    fn inv(self) -> Modulo {
        self.pow(Modulo::get_modulus() - 2)
    }
}
impl std::fmt::Display for Modulo {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
        self.0.fmt(f)
    }
}
impl std::ops::AddAssign for Modulo {
    fn add_assign(&mut self, other: Modulo) {
        let m = Modulo::get_modulus();
        self.0 += other.0;
        if self.0 >= m {
            self.0 -= m;
        }
    }
}
impl std::ops::MulAssign for Modulo {
    fn mul_assign(&mut self, other: Modulo) {
        let m = Modulo::get_modulus();
        self.0 *= other.0;
        self.0 %= m;
    }
}
impl std::ops::SubAssign for Modulo {
    fn sub_assign(&mut self, other: Modulo) {
        let m = Modulo::get_modulus();
        self.0 += m - other.0;
        if self.0 >= m {
            self.0 -= m;
        }
    }
}
macro_rules! impl_modulo_ops {
    ($imp:ident, $method:ident, $assign_imp:ident, $assign_method:ident) => {
        impl<'a> std::ops::$assign_imp<&'a Modulo> for Modulo {
            fn $assign_method(&mut self, other: &'a Modulo) {
                std::ops::$assign_imp::$assign_method(self, *other);
            }
        }
        impl std::ops::$imp for Modulo {
            type Output = Modulo;
            fn $method(self, other: Modulo) -> Modulo {
                let mut x = self;
                std::ops::$assign_imp::$assign_method(&mut x, other);
                x
            }
        }
        impl<'a> std::ops::$imp<Modulo> for &'a Modulo {
            type Output = Modulo;
            fn $method(self, other: Modulo) -> Modulo {
                std::ops::$imp::$method(*self, other)
            }
        }
        impl<'a> std::ops::$imp<&'a Modulo> for Modulo {
            type Output = Modulo;
            fn $method(self, other: &'a Modulo) -> Modulo {
                std::ops::$imp::$method(self, *other)
            }
        }
        impl<'a, 'b> std::ops::$imp<&'b Modulo> for &'a Modulo {
            type Output = Modulo;
            fn $method(self, other: &'b Modulo) -> Modulo {
                std::ops::$imp::$method(*self, *other)
            }
        }
        impl std::ops::$assign_imp<i64> for Modulo {
            fn $assign_method(&mut self, other: i64) {
                std::ops::$assign_imp::$assign_method(self, Modulo::new(other));
            }
        }
        impl<'a> std::ops::$assign_imp<&'a i64> for Modulo {
            fn $assign_method(&mut self, other: &'a i64) {
                std::ops::$assign_imp::$assign_method(self, *other);
            }
        }
        impl std::ops::$imp<i64> for Modulo {
            type Output = Modulo;
            fn $method(self, other: i64) -> Modulo {
                let mut x = self;
                std::ops::$assign_imp::$assign_method(&mut x, other);
                x
            }
        }
        impl<'a> std::ops::$imp<&'a i64> for Modulo {
            type Output = Modulo;
            fn $method(self, other: &'a i64) -> Modulo {
                std::ops::$imp::$method(self, *other)
            }
        }
        impl<'a> std::ops::$imp<i64> for &'a Modulo {
            type Output = Modulo;
            fn $method(self, other: i64) -> Modulo {
                std::ops::$imp::$method(*self, other)
            }
        }
        impl<'a, 'b> std::ops::$imp<&'b i64> for &'a Modulo {
            type Output = Modulo;
            fn $method(self, other: &'b i64) -> Modulo {
                std::ops::$imp::$method(*self, *other)
            }
        }
    };
}
impl_modulo_ops!(Add, add, AddAssign, add_assign);
impl_modulo_ops!(Mul, mul, MulAssign, mul_assign);
impl_modulo_ops!(Sub, sub, SubAssign, sub_assign);

use std::iter::Sum;
impl Sum for Modulo {
    fn sum<I>(iter: I) -> Self
    where
        I: Iterator<Item = Modulo>,
    {
        iter.fold(Modulo(0), |a, b| a + b)
    }
}

impl<'a> Sum<&'a Modulo> for Modulo {
    fn sum<I>(iter: I) -> Self
    where
        I: Iterator<Item = &'a Self>,
    {
        iter.fold(Modulo(0), |a, b| a + b)
    }
}

use std::iter::Product;
impl Product for Modulo {
    fn product<I>(iter: I) -> Self
    where
        I: Iterator<Item = Modulo>,
    {
        iter.fold(Modulo(1), |a, b| a * b)
    }
}

impl<'a> Product<&'a Modulo> for Modulo {
    fn product<I>(iter: I) -> Self
    where
        I: Iterator<Item = &'a Self>,
    {
        iter.fold(Modulo(1), |a, b| a * b)
    }
}

fn mod_comb(n: usize, k: usize, fact: &[Modulo], fact_inv: &[Modulo]) -> Modulo {
    assert!(n >= k);
    fact[n] * fact_inv[n - k] * fact_inv[k]
}

fn factorize(mut num: i64, primes: &Vec<i64>) -> std::collections::HashMap<i64, i64> {
    // max_primes >= (num)^(1/2)
    let num_org = num;
    let mut dict = std::collections::HashMap::new();
    for &p in primes.iter() {
        while num % p == 0 {
            *dict.entry(p).or_insert(0) += 1;
            num /= p;
        }
        if num == 1 {
            break;
        }
        if p * p > num_org {
            *dict.entry(num).or_insert(0) += 1;
            break;
        }
    }
    if num != 1 {
        dict.insert(num, 1);
    }
    dict
}

fn get_primes(n: i64) -> Vec<i64> {
    let mut is_prime = vec![true; n as usize + 1];
    let mut primes = Vec::new();
    is_prime[0] = false;
    is_prime[1] = false;

    for i in 2..n + 1 {
        if is_prime[i as usize] {
            primes.push(i);
            let mut j = 2 * i;
            while j <= n {
                is_prime[j as usize] = false;
                j += i;
            }
        }
    }
    primes
}