#934331 (Rust) No.2561 みんな大好きmod 998

• 問題: No.2561 みんな大好きmod 998
• ユーザー: tipstar0125
• 提出日時: 2023-12-02 15:10:15
• 言語: Rust (1.83.0 + proconio)
• 結果: AC
• 実行時間: 604 ms / 4,000 ms
• コード長: 7,730 bytes
• コンパイル時間: 14,655 ms
• コンパイル使用メモリ: 382,976 KB
• 実行使用メモリ: 317,696 KB
• 最終ジャッジ日時: 2024-09-26 18:12:29
• 合計ジャッジ時間: 24,006 ms
• ジャッジサーバーID （参考情報）: judge2 / judge4

ファイルパターン	結果
sample	AC * 3
other	AC * 44

ソースコード

#![allow(non_snake_case)]
#![allow(unused_imports)]
#![allow(unused_macros)]
#![allow(clippy::needless_range_loop)]
#![allow(clippy::comparison_chain)]
#![allow(clippy::nonminimal_bool)]
#![allow(clippy::neg_multiply)]
#![allow(dead_code)]
use std::cmp::Reverse;
use std::collections::{BTreeMap, BTreeSet, BinaryHeap, VecDeque};

const MOD: usize = 998244353;

#[derive(Default)]
struct Solver {}
impl Solver {
    fn solve(&mut self) {
        input! {
            N: usize,
            K: usize,
            A: [usize; N]
        }

        let v: Vec<usize> = (0..N).collect();
        let mut c = vec![];
        let mut comb = vec![];
        dfs_combination(0, 0, K, &v, &mut c, &mut comb);
        let mut ans = 0_usize;
        for c in comb.iter() {
            let mut S1 = 0_usize;
            let mut S2 = 0_usize;
            for i in c.iter() {
                S1 += A[*i];
                S1 %= 998;
                S2 += A[*i];
                S2 %= MOD;
            }
            if S1 >= S2 {
                ans += 1;
                ans %= 998;
            }
        }
        println!("{}", ans);
    }
}

fn dfs_combination(
    depth: usize,
    s: usize,
    r: usize,
    v: &[usize],
    c: &mut Vec<usize>,
    comb: &mut Vec<Vec<usize>>,
) {
    if depth == r {
        comb.push(c.clone());
        return;
    }
    for i in s..v.len() {
        let x = v[i];
        c.push(x);
        dfs_combination(depth + 1, i + 1, r, v, c, comb);
        c.pop();
    }
}

type Mod = ModInt;
#[derive(Debug, Clone, Copy, Default)]
struct ModInt {
    value: usize,
}

impl ModInt {
    fn new(n: usize) -> Self {
        ModInt { value: n % MOD }
    }
    fn zero() -> Self {
        ModInt { value: 0 }
    }
    fn one() -> Self {
        ModInt { value: 1 }
    }
    fn value(&self) -> usize {
        self.value
    }
    fn pow(&self, n: usize) -> Self {
        let mut p = *self;
        let mut ret = ModInt::one();
        let mut nn = n;
        while nn > 0 {
            if nn & 1 == 1 {
                ret *= p;
            }
            p *= p;
            nn >>= 1;
        }
        ret
    }
    fn inv(&self) -> Self {
        fn ext_gcd(a: usize, b: usize) -> (isize, isize, usize) {
            if a == 0 {
                return (0, 1, b);
            }
            let (x, y, g) = ext_gcd(b % a, a);
            (y - b as isize / a as isize * x, x, g)
        }

        ModInt::new((ext_gcd(self.value, MOD).0 + MOD as isize) as usize)
    }
}

impl std::ops::Add for ModInt {
    type Output = ModInt;
    fn add(self, other: Self) -> Self {
        ModInt::new(self.value + other.value)
    }
}

impl std::ops::Sub for ModInt {
    type Output = ModInt;
    fn sub(self, other: Self) -> Self {
        ModInt::new(MOD + self.value - other.value)
    }
}

impl std::ops::Mul for ModInt {
    type Output = ModInt;
    fn mul(self, other: Self) -> Self {
        ModInt::new(self.value * other.value)
    }
}

#[allow(clippy::suspicious_arithmetic_impl)]
impl std::ops::Div for ModInt {
    type Output = ModInt;
    fn div(self, other: Self) -> Self {
        self * other.inv()
    }
}

impl std::ops::AddAssign for ModInt {
    fn add_assign(&mut self, other: Self) {
        *self = *self + other;
    }
}

impl std::ops::SubAssign for ModInt {
    fn sub_assign(&mut self, other: Self) {
        *self = *self - other;
    }
}

impl std::ops::MulAssign for ModInt {
    fn mul_assign(&mut self, other: Self) {
        *self = *self * other;
    }
}

impl std::ops::DivAssign for ModInt {
    fn div_assign(&mut self, other: Self) {
        *self = *self / other;
    }
}

fn main() {
    std::thread::Builder::new()
        .stack_size(128 * 1024 * 1024)
        .spawn(|| Solver::default().solve())
        .unwrap()
        .join()
        .unwrap();
}

#[macro_export]
macro_rules! input {
    () => {};
    (mut $var:ident: $t:tt, $($rest:tt)*) => {
        let mut $var = __input_inner!($t);
        input!($($rest)*)
    };
    ($var:ident: $t:tt, $($rest:tt)*) => {
        let $var = __input_inner!($t);
        input!($($rest)*)
    };
    (mut $var:ident: $t:tt) => {
        let mut $var = __input_inner!($t);
    };
    ($var:ident: $t:tt) => {
        let $var = __input_inner!($t);
    };
}

#[macro_export]
macro_rules! __input_inner {
    (($($t:tt),*)) => {
        ($(__input_inner!($t)),*)
    };
    ([$t:tt; $n:expr]) => {
        (0..$n).map(|_| __input_inner!($t)).collect::<Vec<_>>()
    };
    ([$t:tt]) => {{
        let n = __input_inner!(usize);
        (0..n).map(|_| __input_inner!($t)).collect::<Vec<_>>()
    }};
    (chars) => {
        __input_inner!(String).chars().collect::<Vec<_>>()
    };
    (bytes) => {
        __input_inner!(String).into_bytes()
    };
    (usize1) => {
        __input_inner!(usize) - 1
    };
    ($t:ty) => {
        $crate::read::<$t>()
    };
}

#[macro_export]
macro_rules! println {
    () => {
        $crate::write(|w| {
            use std::io::Write;
            std::writeln!(w).unwrap()
        })
    };
    ($($arg:tt)*) => {
        $crate::write(|w| {
            use std::io::Write;
            std::writeln!(w, $($arg)*).unwrap()
        })
    };
}

#[macro_export]
macro_rules! print {
    ($($arg:tt)*) => {
        $crate::write(|w| {
            use std::io::Write;
            std::write!(w, $($arg)*).unwrap()
        })
    };
}

#[macro_export]
macro_rules! flush {
    () => {
        $crate::write(|w| {
            use std::io::Write;
            w.flush().unwrap()
        })
    };
}

pub fn read<T>() -> T
where
    T: std::str::FromStr,
    T::Err: std::fmt::Debug,
{
    use std::cell::RefCell;
    use std::io::*;

    thread_local! {
        pub static STDIN: RefCell<StdinLock<'static>> = RefCell::new(stdin().lock());
    }

    STDIN.with(|r| {
        let mut r = r.borrow_mut();
        let mut s = vec![];
        loop {
            let buf = r.fill_buf().unwrap();
            if buf.is_empty() {
                break;
            }
            if let Some(i) = buf.iter().position(u8::is_ascii_whitespace) {
                s.extend_from_slice(&buf[..i]);
                r.consume(i + 1);
                if !s.is_empty() {
                    break;
                }
            } else {
                s.extend_from_slice(buf);
                let n = buf.len();
                r.consume(n);
            }
        }
        std::str::from_utf8(&s).unwrap().parse().unwrap()
    })
}

pub fn write<F>(f: F)
where
    F: FnOnce(&mut std::io::BufWriter<std::io::StdoutLock>),
{
    use std::cell::RefCell;
    use std::io::*;

    thread_local! {
        pub static STDOUT: RefCell<BufWriter<StdoutLock<'static>>> =
            RefCell::new(BufWriter::new(stdout().lock()));
    }

    STDOUT.with(|w| f(&mut w.borrow_mut()))
}

trait Bound<T> {
    fn lower_bound(&self, x: &T) -> usize;
    fn upper_bound(&self, x: &T) -> usize;
}

impl<T: PartialOrd> Bound<T> for [T] {
    fn lower_bound(&self, x: &T) -> usize {
        let (mut low, mut high) = (0, self.len());
        while low + 1 < high {
            let mid = (low + high) / 2;
            if self[mid] < *x {
                low = mid;
            } else {
                high = mid;
            }
        }
        if self[low] < *x {
            low + 1
        } else {
            low
        }
    }

    fn upper_bound(&self, x: &T) -> usize {
        let (mut low, mut high) = (0, self.len());
        while low + 1 < high {
            let mid = (low + high) / 2;
            if self[mid] <= *x {
                low = mid;
            } else {
                high = mid;
            }
        }
        if self[low] <= *x {
            low + 1
        } else {
            low
        }
    }
}