結果

問題 No.2742 Car Flow
コンテスト
ユーザー t33f
提出日時 2024-04-21 12:50:04
言語 Rust
(1.83.0 + proconio)
結果
AC  
実行時間 6 ms / 2,000 ms
コード長 3,962 bytes
コンパイル時間 13,687 ms
コンパイル使用メモリ 378,360 KB
実行使用メモリ 5,248 KB
最終ジャッジ日時 2024-10-13 11:21:13
合計ジャッジ時間 15,614 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge4
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 * 1
other AC * 50
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 # 

#![allow(non_snake_case)]
use proconio::{input};

mod mod_int {
use core::iter::Sum;
use core::ops::*;

#[derive(Copy, Clone, Hash, PartialEq, Eq, Debug)]
pub struct ModInt<const MOD: i32> {
    value: i32
}

impl<const MOD: i32> ModInt<MOD> {
    fn normalize(v: i64) -> i32 {
        if 0 <= v && v < MOD as i64 {
            v as i32
        } else {
            let v1 = (v % MOD as i64) as i32;
            if v1 < 0 { v1 + MOD } else { v1 }
        }
    }
    pub fn new(v: i64) -> ModInt<MOD> { ModInt{ value: Self::normalize(v) } }
    pub fn inverse(self) -> Self {
        let mut x = MOD as i64;
        let mut y = self.value as i64;
        let mut p = 1;
        let mut q = 0;
        let mut r = 0;
        let mut s = 1;
        while y != 0 {
            let u = x / y;
            let x0 = y; y = x - y * u; x = x0;
            let r0 = p - r * u;
            let s0 = q - s * u;
            p = r; r = r0; q = s; s = s0;
        }
        ModInt::new(q)
    }
}

impl<const MOD: i32> std::fmt::Display for ModInt<MOD> {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "{}", self.value)
    }
}

impl<const MOD: i32> Add<Self> for ModInt<MOD> {
    type Output = Self;
    fn add(self, rhs: Self) -> Self {
        let value = self.value as i64 + rhs.value as i64;
        let value = (if value < MOD as i64 { value } else { value - MOD as i64 }) as i32;
        ModInt{ value }
    }
}

impl<const MOD: i32> Add<i64> for ModInt<MOD> {
    type Output = Self;
    fn add(self, rhs: i64) -> Self {
        self + ModInt::new(rhs)
    }
}

impl<const MOD: i32> Sub<Self> for ModInt<MOD> {
    type Output = Self;
    fn sub(self, rhs: Self) -> Self {
        let value = self.value as i64 - rhs.value as i64;
        let value = (if value >= 0 { value } else { value + MOD as i64 }) as i32;
        ModInt{ value }
    }
}

impl<const MOD: i32> Sub<i64> for ModInt<MOD> {
    type Output = Self;
    fn sub(self, rhs: i64) -> Self {
        self - ModInt::new(rhs)
    }
}

impl<const MOD: i32> AddAssign<Self> for ModInt<MOD> {
    fn add_assign(&mut self, rhs: Self) {
        *self = *self + rhs
    }
}

impl<const MOD: i32> AddAssign<i64> for ModInt<MOD> {
    fn add_assign(&mut self, rhs: i64) {
        *self = *self + rhs
    }
}

impl<const MOD: i32> Mul<Self> for ModInt<MOD> {
    type Output = Self;
    fn mul(self, rhs: Self) -> Self {
        Self::new(self.value as i64 * rhs.value as i64)
    }
}

impl<const MOD: i32> MulAssign<Self> for ModInt<MOD> {
    fn mul_assign(&mut self, rhs: Self) {
        *self = *self * rhs
    }
}

impl<const MOD: i32> Div<Self> for ModInt<MOD> {
    type Output = Self;
    fn div(self, rhs: Self) -> Self {
        self * rhs.inverse()
    }
}

impl<const MOD: i32> Div<i64> for ModInt<MOD> {
    type Output = Self;
    fn div(self, rhs: i64) -> Self {
        self / ModInt::new(rhs)
    }
}

impl<const MOD: i32> Sum<Self> for ModInt<MOD> {
    fn sum<I: Iterator<Item=Self>>(iter: I) -> Self {
        iter.fold(Self::new(0), |a, b| a + b)
    }
}
}

const MOD: i32 = 998244353;
type MInt = mod_int::ModInt::<MOD>;

fn main() {
    input!{ n: usize, a: [usize; n] }
    // {
    //     let mut b = a.clone();
    //     for _ in 0..1000 {
    //         let mut c = b.clone();
    //         for i in 0..n {
    //             c[i] = if {
    //                 (b[(i + n - 1) % n] == 1 && b[i] == 0) ||
    //                     (b[i] == 1 && b[(i + 1) % n] == 1)
    //             } {
    //                 1
    //             } else {
    //                 0
    //             }
    //         }
    //         for x in &c { eprint!("{x} "); }
    //         eprintln!("");
    //         b = c;
    //     }
    // }
    let s = a.iter().sum::<usize>();
    if s <= n / 2 {
        println!("{}", MInt::new(s as i64) / MInt::new(n as i64))
    } else {
        println!("{}", MInt::new((n - s) as i64) / MInt::new(n as i64))
    }
}
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