pub use __cargo_equip::prelude::*; use next_permutation::NextPermutation; use scanner::Scanner; use std::io; fn main() { let mut scanner = Scanner::from(io::stdin().lock()); let (n, k) = scan!((usize, usize), <~ scanner); let a = scan!([u64; n], <~ scanner); let mut ord = vec![false; n]; for i in 0..k { ord[i] = true; } ord.sort(); let mut ans = 0; loop { let mut s1 = 0; let mut s2 = 0; for (i, &f) in ord.iter().enumerate() { if f == false { continue; } s1 += a[i]; s1 %= 998244353; s2 += a[i]; s2 %= 998; } if s1 <= s2 { ans += 1; ans %= 998; } if ord.next_permutation() == false { break; } } println!("{}", ans); } // ✂ --- scanner --- ✂ #[allow(unused)] mod scanner { pub use crate::__cargo_equip::prelude::*; use std::fmt; use std::io; use std::str; pub struct Scanner { r: R, l: String, i: usize, } impl Scanner where R: io::BufRead, { pub fn new(reader: R) -> Self { Self { r: reader, l: String::new(), i: 0, } } pub fn scan(&mut self) -> T where T: str::FromStr, T::Err: fmt::Debug, { self.skip_blanks(); assert!(self.i < self.l.len()); // remain some character assert_ne!(&self.l[self.i..=self.i], " "); let rest = &self.l[self.i..]; let len = rest .find(|ch| char::is_ascii_whitespace(&ch)) .unwrap_or_else(|| rest.len()); // parse self.l[self.i..(self.i + len)] let val = rest[..len] .parse() .unwrap_or_else(|e| panic!("{:?}, attempt to read `{}`", e, rest)); self.i += len; val } pub fn scan_vec(&mut self, n: usize) -> Vec where T: str::FromStr, T::Err: fmt::Debug, { (0..n).map(|_| self.scan()).collect::>() } fn skip_blanks(&mut self) { loop { match self.l[self.i..].find(|ch| !char::is_ascii_whitespace(&ch)) { Some(j) => { self.i += j; break; } None => { self.l.clear(); // clear buffer let num_bytes = self .r .read_line(&mut self.l) .unwrap_or_else(|_| panic!("invalid UTF-8")); assert!(num_bytes > 0, "reached EOF :("); self.i = 0; } } } } } impl<'a> From<&'a str> for Scanner<&'a [u8]> { fn from(s: &'a str) -> Self { Self::new(s.as_bytes()) } } impl<'a> From> for Scanner>> { fn from(stdin: io::StdinLock<'a>) -> Self { Self::new(io::BufReader::new(stdin)) } } #[macro_export] macro_rules! scan { (( $($t: ty),+ ), <~ $scanner: expr) => { ( $(scan!($t, <~ $scanner)),+ ) }; ([ $t: tt; $n: expr ], <~ $scanner: expr) => { (0..$n).map(|_| scan!($t, <~ $scanner)).collect::>() }; ($t: ty, <~ $scanner: expr) => { $scanner.scan::<$t>() }; } } // ✂ --- scanner --- ✂ // The following code was expanded by `cargo-equip`. /// # Bundled libraries /// /// - `next_permutation 0.1.0 (git+https://github.com/ia7ck/rust-competitive-programming#f49de25336b2de6602bce284a44ec4b9d163e9f4)` licensed under `CC0-1.0` as `crate::__cargo_equip::crates::next_permutation` #[allow(unused)] mod __cargo_equip { pub(crate) mod crates { pub mod next_permutation { pub trait NextPermutation { fn next_permutation(&mut self) -> bool; } impl NextPermutation for [T] { fn next_permutation(&mut self) -> bool { if self.len() <= 1 { return false; } let mut i = self.len() - 1; while i > 0 && self[i - 1] >= self[i] { i -= 1; } if i == 0 { return false; } let mut j = self.len() - 1; while self[i - 1] >= self[j] { j -= 1; } self.swap(i - 1, j); self[i..].reverse(); true } } } } pub(crate) mod macros { pub mod next_permutation {} } pub(crate) mod prelude { pub use crate::__cargo_equip::crates::*; } mod preludes { pub mod next_permutation {} } }