結果

問題 No.1554 array_and_me
ユーザー akakimidori
提出日時 2021-06-18 22:41:28
言語 Rust
(1.83.0 + proconio)
結果
AC  
実行時間 53 ms / 2,000 ms
コード長 9,225 bytes
コンパイル時間 12,643 ms
コンパイル使用メモリ 378,680 KB
実行使用メモリ 8,576 KB
最終ジャッジ日時 2024-06-22 21:04:48
合計ジャッジ時間 15,304 ms
ジャッジサーバーID
(参考情報)
judge2 / judge3
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 * 41
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 #
プレゼンテーションモードにする

// ---------- begin ModInt ----------
mod modint {
#[allow(dead_code)]
pub struct Mod;
impl ConstantModulo for Mod {
const MOD: u32 = 998_244_353;
}
#[allow(dead_code)]
pub struct StaticMod;
static mut STATIC_MOD: u32 = 0;
impl Modulo for StaticMod {
fn modulo() -> u32 {
unsafe { STATIC_MOD }
}
}
#[allow(dead_code)]
impl StaticMod {
pub fn set_modulo(p: u32) {
unsafe {
STATIC_MOD = p;
}
}
}
use std::marker::*;
use std::ops::*;
pub trait Modulo {
fn modulo() -> u32;
}
pub trait ConstantModulo {
const MOD: u32;
}
impl<T> Modulo for T
where
T: ConstantModulo,
{
fn modulo() -> u32 {
T::MOD
}
}
pub struct ModInt<T>(pub u32, PhantomData<T>);
impl<T> Clone for ModInt<T> {
fn clone(&self) -> Self {
ModInt::new_unchecked(self.0)
}
}
impl<T> Copy for ModInt<T> {}
impl<T: Modulo> Add for ModInt<T> {
type Output = ModInt<T>;
fn add(self, rhs: Self) -> Self::Output {
let mut d = self.0 + rhs.0;
if d >= T::modulo() {
d -= T::modulo();
}
ModInt::new_unchecked(d)
}
}
impl<T: Modulo> AddAssign for ModInt<T> {
fn add_assign(&mut self, rhs: Self) {
*self = *self + rhs;
}
}
impl<T: Modulo> Sub for ModInt<T> {
type Output = ModInt<T>;
fn sub(self, rhs: Self) -> Self::Output {
let mut d = T::modulo() + self.0 - rhs.0;
if d >= T::modulo() {
d -= T::modulo();
}
ModInt::new_unchecked(d)
}
}
impl<T: Modulo> SubAssign for ModInt<T> {
fn sub_assign(&mut self, rhs: Self) {
*self = *self - rhs;
}
}
impl<T: Modulo> Mul for ModInt<T> {
type Output = ModInt<T>;
fn mul(self, rhs: Self) -> Self::Output {
let v = self.0 as u64 * rhs.0 as u64 % T::modulo() as u64;
ModInt::new_unchecked(v as u32)
}
}
impl<T: Modulo> MulAssign for ModInt<T> {
fn mul_assign(&mut self, rhs: Self) {
*self = *self * rhs;
}
}
impl<T: Modulo> Neg for ModInt<T> {
type Output = ModInt<T>;
fn neg(self) -> Self::Output {
if self.0 == 0 {
Self::zero()
} else {
Self::new_unchecked(T::modulo() - self.0)
}
}
}
impl<T> std::fmt::Display for ModInt<T> {
fn fmt<'a>(&self, f: &mut std::fmt::Formatter<'a>) -> std::fmt::Result {
write!(f, "{}", self.0)
}
}
impl<T> std::fmt::Debug for ModInt<T> {
fn fmt<'a>(&self, f: &mut std::fmt::Formatter<'a>) -> std::fmt::Result {
write!(f, "{}", self.0)
}
}
impl<T: Modulo> std::str::FromStr for ModInt<T> {
type Err = std::num::ParseIntError;
fn from_str(s: &str) -> Result<Self, Self::Err> {
let val = s.parse::<u32>()?;
Ok(ModInt::new(val))
}
}
impl<T: Modulo> From<usize> for ModInt<T> {
fn from(val: usize) -> ModInt<T> {
ModInt::new_unchecked((val % T::modulo() as usize) as u32)
}
}
impl<T: Modulo> From<u64> for ModInt<T> {
fn from(val: u64) -> ModInt<T> {
ModInt::new_unchecked((val % T::modulo() as u64) as u32)
}
}
impl<T: Modulo> From<i64> for ModInt<T> {
fn from(val: i64) -> ModInt<T> {
let m = T::modulo() as i64;
ModInt::new((val % m + m) as u32)
}
}
#[allow(dead_code)]
impl<T> ModInt<T> {
pub fn new_unchecked(d: u32) -> Self {
ModInt(d, PhantomData)
}
pub fn zero() -> Self {
ModInt::new_unchecked(0)
}
pub fn one() -> Self {
ModInt::new_unchecked(1)
}
pub fn is_zero(&self) -> bool {
self.0 == 0
}
}
#[allow(dead_code)]
impl<T: Modulo> ModInt<T> {
pub fn new(d: u32) -> Self {
ModInt::new_unchecked(d % T::modulo())
}
pub fn pow(&self, mut n: u64) -> Self {
let mut t = Self::one();
let mut s = *self;
while n > 0 {
if n & 1 == 1 {
t *= s;
}
s *= s;
n >>= 1;
}
t
}
pub fn inv(&self) -> Self {
assert!(self.0 != 0);
self.pow(T::modulo() as u64 - 2)
}
}
}
// ---------- end ModInt ----------
// ---------- begin Precalc ----------
mod precalc {
use super::modint::*;
#[allow(dead_code)]
pub struct Precalc<T> {
inv: Vec<ModInt<T>>,
fact: Vec<ModInt<T>>,
ifact: Vec<ModInt<T>>,
}
#[allow(dead_code)]
impl<T: Modulo> Precalc<T> {
pub fn new(n: usize) -> Precalc<T> {
let mut inv = vec![ModInt::one(); n + 1];
let mut fact = vec![ModInt::one(); n + 1];
let mut ifact = vec![ModInt::one(); n + 1];
for i in 2..(n + 1) {
fact[i] = fact[i - 1] * ModInt::new_unchecked(i as u32);
}
ifact[n] = fact[n].inv();
if n > 0 {
inv[n] = ifact[n] * fact[n - 1];
}
for i in (1..n).rev() {
ifact[i] = ifact[i + 1] * ModInt::new_unchecked((i + 1) as u32);
inv[i] = ifact[i] * fact[i - 1];
}
Precalc {
inv: inv,
fact: fact,
ifact: ifact,
}
}
pub fn inv(&self, n: usize) -> ModInt<T> {
assert!(n > 0);
self.inv[n]
}
pub fn fact(&self, n: usize) -> ModInt<T> {
self.fact[n]
}
pub fn ifact(&self, n: usize) -> ModInt<T> {
self.ifact[n]
}
pub fn perm(&self, n: usize, k: usize) -> ModInt<T> {
if k > n {
return ModInt::zero();
}
self.fact[n] * self.ifact[n - k]
}
pub fn comb(&self, n: usize, k: usize) -> ModInt<T> {
if k > n {
return ModInt::zero();
}
self.fact[n] * self.ifact[k] * self.ifact[n - k]
}
}
}
// ---------- end Precalc ----------
use modint::*;
type M = ModInt<Mod>;
// ---------- begin scannner ----------
#[allow(dead_code)]
mod scanner {
use std::str::FromStr;
pub struct Scanner<'a> {
it: std::str::SplitWhitespace<'a>,
}
impl<'a> Scanner<'a> {
pub fn new(s: &'a String) -> Scanner<'a> {
Scanner {
it: s.split_whitespace(),
}
}
pub fn next<T: FromStr>(&mut self) -> T {
self.it.next().unwrap().parse::<T>().ok().unwrap()
}
pub fn next_bytes(&mut self) -> Vec<u8> {
self.it.next().unwrap().bytes().collect()
}
pub fn next_chars(&mut self) -> Vec<char> {
self.it.next().unwrap().chars().collect()
}
pub fn next_vec<T: FromStr>(&mut self, len: usize) -> Vec<T> {
(0..len).map(|_| self.next()).collect()
}
}
}
// ---------- end scannner ----------
use std::io::Write;
fn main() {
use std::io::Read;
let mut s = String::new();
std::io::stdin().read_to_string(&mut s).unwrap();
let mut sc = scanner::Scanner::new(&s);
let out = std::io::stdout();
let mut out = std::io::BufWriter::new(out.lock());
run(&mut sc, &mut out);
}
// sum A_i = S
// p_i = A_i / S
// (1 + p_i / 1! * x + p_i^2 / 2! * x^2 + ...)
#[derive(Clone, Copy, Eq, PartialEq, Debug)]
struct Frac {
nu: usize,
de: usize,
}
use std::cmp::*;
impl Ord for Frac {
fn cmp(&self, rhs: &Self) -> Ordering {
(self.nu * rhs.de).cmp(&(self.de * rhs.nu))
}
}
impl PartialOrd for Frac {
fn partial_cmp(&self, rhs: &Self) -> Option<Ordering> {
Some(self.cmp(rhs))
}
}
impl Frac {
fn new(nu: usize, de: usize) -> Self {
Frac {
nu,
de,
}
}
}
fn run<W: Write>(sc: &mut scanner::Scanner, out: &mut std::io::BufWriter<W>) {
let t: u32 = sc.next();
for _ in 0..t {
let n: usize = sc.next();
let k: usize = sc.next();
let a: Vec<usize> = sc.next_vec(n);
let s = a.iter().sum::<usize>();
let mut cnt = vec![0; n];
let mut h = std::collections::BinaryHeap::new();
for (i, a) in a.iter().enumerate() {
h.push((Frac::new(*a, 1), i));
}
for _ in 0..k {
let (_, k) = h.pop().unwrap();
cnt[k] += 1;
h.push((Frac::new(a[k], cnt[k] + 1), k));
}
let pc = precalc::Precalc::new(n + k);
let mut ans = pc.fact(k);
for i in 0..n {
ans *= (M::from(a[i]) * M::from(s).inv()).pow(cnt[i] as u64) * pc.ifact(cnt[i]);
}
writeln!(out, "{}", ans).ok();
}
}
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