結果

問題 No.1299 Random Array Score
コンテスト
ユーザー ikd
提出日時 2020-12-13 11:06:19
言語 Rust
(1.83.0 + proconio)
結果
AC  
実行時間 16 ms / 2,000 ms
コード長 4,117 bytes
コンパイル時間 13,305 ms
コンパイル使用メモリ 378,368 KB
実行使用メモリ 6,272 KB
最終ジャッジ日時 2024-09-19 23:26:50
合計ジャッジ時間 15,023 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge5
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 34
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 # 

fn main() {
    let stdin = std::io::stdin();
    let mut rd = ProconReader::new(stdin.lock());

    let n: usize = rd.get();
    let k: usize = rd.get();
    let a: Vec<i64> = (0..n).map(|_| rd.get()).collect();

    type Mint = ModInt998244353;
    let sum = a.iter().fold(Mint::new(0), |acc, &x| acc + Mint::new(x));
    let ans = sum * Mint::new(2).pow(k as u64);
    println!("{}", ans.val());
}

use std::fmt::Debug;
use std::marker::PhantomData;
use std::ops::{Add, Div, Mul, Sub};

pub trait Modulo: Copy + Clone + Debug {
    fn p() -> i64;
}

#[derive(Copy, Clone, Debug)]
pub struct ModInt<M>(i64, PhantomData<M>);

impl<M: Modulo> ModInt<M> {
    pub fn new(x: i64) -> Self {
        Self(x.rem_euclid(M::p()), PhantomData)
    }
    pub fn val(self) -> i64 {
        self.0
    }
    pub fn mo(self) -> i64 {
        M::p()
    }
    pub fn pow(self, exp: u64) -> Self {
        let mut res = Self::new(1);
        let mut base = self;
        let mut exp = exp;
        while exp > 0 {
            if exp & 1 == 1 {
                res = res * base;
            }
            base = base * base;
            exp >>= 1;
        }
        res
    }
    pub fn inv(self) -> Self {
        assert_ne!(self.0, 0, "Don't divide by zero!");
        self.pow(M::p() as u64 - 2)
    }
    pub fn new_frac(numer: i64, denom: i64) -> Self {
        Self::new(numer) / Self::new(denom)
    }
}

impl<M: Modulo> Add for ModInt<M> {
    type Output = ModInt<M>;
    fn add(self, rhs: ModInt<M>) -> Self::Output {
        Self((self.0 + rhs.0) % M::p(), PhantomData)
    }
}

impl<M: Modulo> Sub for ModInt<M> {
    type Output = ModInt<M>;
    fn sub(self, rhs: ModInt<M>) -> Self::Output {
        Self((self.0 - rhs.0).rem_euclid(M::p()), PhantomData)
    }
}

impl<M: Modulo> Mul for ModInt<M> {
    type Output = ModInt<M>;
    fn mul(self, rhs: ModInt<M>) -> Self::Output {
        Self((self.0 * rhs.0) % M::p(), PhantomData)
    }
}

impl<M: Modulo> Div for ModInt<M> {
    type Output = ModInt<M>;
    fn div(self, rhs: ModInt<M>) -> Self::Output {
        self * rhs.inv()
    }
}

macro_rules! define_mod_int_p {
    ($mod: ident, $mod_int: ident, $p: expr) => {
        #[derive(Clone, Copy, Debug)]
        pub struct $mod;
        impl Modulo for $mod {
            fn p() -> i64 {
                $p
            }
        }
        pub type $mod_int = ModInt<$mod>;
    };
}
define_mod_int_p!(Mod1000000007, ModInt1000000007, 100000007);
define_mod_int_p!(Mod998244353, ModInt998244353, 998244353);

pub struct ProconReader<R> {
    r: R,
    line: String,
    i: usize,
}

impl<R: std::io::BufRead> ProconReader<R> {
    pub fn new(reader: R) -> Self {
        Self {
            r: reader,
            line: String::new(),
            i: 0,
        }
    }
    pub fn get<T>(&mut self) -> T
    where
        T: std::str::FromStr,
        <T as std::str::FromStr>::Err: std::fmt::Debug,
    {
        self.skip_blanks();
        assert!(self.i < self.line.len());
        assert_ne!(&self.line[self.i..=self.i], " ");
        let line = &self.line[self.i..];
        let end = line.find(' ').unwrap_or_else(|| line.len());
        let s = &line[..end];
        self.i += end;
        s.parse()
            .unwrap_or_else(|_| panic!("parse error `{}`", self.line))
    }
    fn skip_blanks(&mut self) {
        loop {
            let start = self.line[self.i..].find(|ch| ch != ' ');
            match start {
                Some(j) => {
                    self.i += j;
                    break;
                }
                None => {
                    self.line.clear();
                    self.i = 0;
                    let num_bytes = self.r.read_line(&mut self.line).unwrap();
                    assert!(num_bytes > 0, "reached EOF :(");
                    self.line = self.line.trim_end_matches(&['\r', '\n'][..]).to_string();
                }
            }
        }
    }
    pub fn get_vec<T>(&mut self, n: usize) -> Vec<T>
    where
        T: std::str::FromStr,
        <T as std::str::FromStr>::Err: std::fmt::Debug,
    {
        (0..n).map(|_| self.get()).collect()
    }
}
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