#853248 (Rust) No.2580 Hyperinflation

提出ソース
結果

問題	No.2580 Hyperinflation
ユーザー	akakimidori
提出日時	2023-03-26 17:22:47
言語	Rust (1.77.0 + proconio)
結果	AC
実行時間	797 ms / 4,000 ms
コード長	20,451 bytes
コンパイル時間	13,974 ms
コンパイル使用メモリ	382,596 KB
実行使用メモリ	6,948 KB
最終ジャッジ日時	2024-09-25 16:01:41
合計ジャッジ時間	24,444 ms
ジャッジサーバーID （参考情報）	judge4 / judge3
このコードへのチャレンジ
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テストケース

テストケース表示
入力	結果	実行時間実行使用メモリ
testcase_00	AC	1 ms 6,812 KB
testcase_01	AC	1 ms 6,816 KB
testcase_02	AC	1 ms 6,812 KB
testcase_03	AC	1 ms 6,940 KB
testcase_04	AC	1 ms 6,944 KB
testcase_05	AC	2 ms 6,940 KB
testcase_06	AC	1 ms 6,948 KB
testcase_07	AC	1 ms 6,944 KB
testcase_08	AC	1 ms 6,944 KB
testcase_09	AC	1 ms 6,940 KB
testcase_10	AC	1 ms 6,940 KB
testcase_11	AC	1 ms 6,940 KB
testcase_12	AC	1 ms 6,940 KB
testcase_13	AC	2 ms 6,940 KB
testcase_14	AC	6 ms 6,940 KB
testcase_15	AC	4 ms 6,940 KB
testcase_16	AC	3 ms 6,944 KB
testcase_17	AC	1 ms 6,940 KB
testcase_18	AC	74 ms 6,940 KB
testcase_19	AC	75 ms 6,944 KB
testcase_20	AC	75 ms 6,944 KB
testcase_21	AC	76 ms 6,940 KB
testcase_22	AC	76 ms 6,940 KB
testcase_23	AC	797 ms 6,940 KB
testcase_24	AC	792 ms 6,940 KB
testcase_25	AC	791 ms 6,940 KB
testcase_26	AC	790 ms 6,940 KB
testcase_27	AC	792 ms 6,940 KB
testcase_28	AC	791 ms 6,944 KB
testcase_29	AC	791 ms 6,940 KB
testcase_30	AC	793 ms 6,940 KB
testcase_31	AC	792 ms 6,944 KB
testcase_32	AC	655 ms 6,944 KB
testcase_33	AC	660 ms 6,940 KB
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ソースコード

raw source code
fn main() {
    let (a, m) = read();
    let n = a.len() + 1;
    let pc = precalc::Precalc::new(n + 2);
    let mut f = vec![M::zero(); n + 1];
    for (i, f) in f.iter_mut().enumerate() {
        *f = pc.ifact(i + 1);
    }
    let mut bernoulli = f.inverse(n + 1);
    bernoulli[1] = -bernoulli[1];
    let prefix_sum = |mut a: Vec<M>| -> Vec<M> {
        let z = std::mem::replace(&mut a[0], M::zero());
        let n = a.len();
        for (i, a) in a.iter_mut().enumerate() {
            *a *= pc.fact(i);
        }
        a.reverse();
        a = a.multiply(&bernoulli[..n]);
        a.truncate(n);
        a.push(M::zero());
        a.reverse();
        for (i, a) in a.iter_mut().enumerate() {
            *a *= pc.ifact(i);
        }
        a[0] += z;
        a[1] += z;
        a
    };
    let taylor_shift = |a: Vec<M>, c: M| -> Vec<M> {
        let mut b = a.clone();
        for (i, b) in b.iter_mut().enumerate() {
            *b *= pc.fact(i);
        }
        b.reverse();
        let mut d = vec![M::one(); a.len()];
        for i in 1..a.len() {
            d[i] = d[i - 1] * c * pc.inv(i);
        }
        let mut res = b.multiply(&d);
        res.truncate(a.len());
        res.reverse();
        for (i, res) in res.iter_mut().enumerate() {
            *res *= pc.ifact(i);
        }
        res
    };
    let mut m = m
        .into_iter()
        .map(|c| (c - b'0') as usize)
        .collect::<Vec<_>>();
    let mut dp = vec![M::one()];
    for &q in a.iter() {
        let rem = div_rem(&mut m, q);
        dp = taylor_shift(dp, M::from(rem));
        for (i, dp) in dp.iter_mut().enumerate() {
            *dp *= M::from(q).pow(i as u64);
        }
        dp = prefix_sum(dp);
    }
    let rem = div_rem(&mut m, 998_244_353);
    let ans = dp.eval(M::from(rem));
    println!("{}", ans);
}

pub fn div_rem(m: &mut [usize], d: usize) -> usize {
    let mut rem = 0;
    for m in m.iter_mut() {
        let v = 10 * rem + *m;
        *m = v / d;
        rem = v % d;
    }
    rem
}

fn read() -> (Vec<usize>, Vec<u8>) {
    use std::io::*;
    let mut s = String::new();
    std::io::stdin().read_to_string(&mut s).unwrap();
    let mut it = s.trim().split_whitespace();
    let n = it.next().unwrap().parse::<usize>().unwrap();
    let a = (1..n)
        .map(|_| it.next().unwrap().parse::<usize>().unwrap())
        .collect::<Vec<_>>();
    let m = it.next().unwrap().bytes().collect();
    (a, m)
}

// ---------- begin ModInt ----------
mod modint {

    use std::marker::*;
    use std::ops::*;

    pub trait Modulo {
        fn modulo() -> u32;
        fn rem() -> u32;
        fn ini() -> u64;
        fn reduce(x: u64) -> u32 {
            debug_assert!(x < (Self::modulo() as u64) << 32);
            let b = (x as u32 * Self::rem()) as u64;
            let t = x + b * Self::modulo() as u64;
            let mut c = (t >> 32) as u32;
            if c >= Self::modulo() {
                c -= Self::modulo();
            }
            c as u32
        }
    }

    #[allow(dead_code)]
    pub enum Mod998_244_353 {}

    impl Modulo for Mod998_244_353 {
        fn modulo() -> u32 {
            998_244_353
        }
        fn rem() -> u32 {
            998244351
        }
        fn ini() -> u64 {
            932051910
        }
    }

    pub struct ModInt<T>(u32, PhantomData<T>);

    impl<T> Clone for ModInt<T> {
        fn clone(&self) -> Self {
            ModInt::build(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();
            }
            Self::build(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 = self.0 - rhs.0;
            if self.0 < rhs.0 {
                d += T::modulo();
            }
            Self::build(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 {
            Self::build(T::reduce(self.0 as u64 * rhs.0 as u64))
        }
    }

    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::build(T::modulo() - self.0)
            }
        }
    }

    impl<T: Modulo> std::fmt::Display for ModInt<T> {
        fn fmt<'a>(&self, f: &mut std::fmt::Formatter<'a>) -> std::fmt::Result {
            write!(f, "{}", self.get())
        }
    }

    impl<T: Modulo> std::fmt::Debug for ModInt<T> {
        fn fmt<'a>(&self, f: &mut std::fmt::Formatter<'a>) -> std::fmt::Result {
            write!(f, "{}", self.get())
        }
    }

    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> {
        fn build(d: u32) -> Self {
            ModInt(d, PhantomData)
        }
        pub fn zero() -> Self {
            Self::build(0)
        }
        pub fn is_zero(&self) -> bool {
            self.0 == 0
        }
    }

    #[allow(dead_code)]
    impl<T: Modulo> ModInt<T> {
        pub fn new_unchecked(d: u32) -> Self {
            Self::build(T::reduce(d as u64 * T::ini()))
        }
        pub fn new(d: u32) -> Self {
            Self::new_unchecked(d % T::modulo())
        }
        pub fn one() -> Self {
            Self::new_unchecked(1)
        }
        pub fn get(&self) -> u32 {
            T::reduce(self.0 as u64)
        }
        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.is_zero());
            self.pow((T::modulo() - 2) as u64)
        }
        pub fn binom(n: usize, k: usize) -> Self {
            if n < k {
                return Self::zero();
            }
            let k = k.min(n - k);
            let mut nu = Self::one();
            let mut de = Self::one();
            for i in 0..k {
                nu *= Self::from(n - i);
                de *= Self::from(i + 1);
            }
            nu * de.inv()
        }
    }
}
// ---------- 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 binom(&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::*;

pub trait NTTFriendly: modint::Modulo {
    fn order() -> usize;
    fn zeta() -> u32;
}

type M = ModInt<Mod998_244_353>;

impl NTTFriendly for Mod998_244_353 {
    fn order() -> usize {
        8388608
    }
    fn zeta() -> u32 {
        15311432
    }
}

use std::ops::*;

pub trait Zero: Sized + Add<Output = Self> {
    fn zero() -> Self;
}

pub fn zero<T: Zero>() -> T {
    T::zero()
}

impl<T: Modulo> Zero for ModInt<T> {
    fn zero() -> Self {
        Self::zero()
    }
}

impl Zero for usize {
    fn zero() -> Self {
        0
    }
}

pub trait ArrayAdd {
    type Item;
    fn add(&self, rhs: &[Self::Item]) -> Vec<Self::Item>;
}

impl<T> ArrayAdd for [T]
where
    T: Zero + Copy,
{
    type Item = T;
    fn add(&self, rhs: &[Self::Item]) -> Vec<Self::Item> {
        let mut c = vec![T::zero(); self.len().max(rhs.len())];
        c[..self.len()].copy_from_slice(self);
        c.add_assign(rhs);
        c
    }
}

pub trait ArrayAddAssign {
    type Item;
    fn add_assign(&mut self, rhs: &[Self::Item]);
}

impl<T> ArrayAddAssign for [T]
where
    T: Add<Output = T> + Copy,
{
    type Item = T;
    fn add_assign(&mut self, rhs: &[Self::Item]) {
        assert!(self.len() >= rhs.len());
        self.iter_mut().zip(rhs).for_each(|(x, a)| *x = *x + *a);
    }
}

impl<T> ArrayAddAssign for Vec<T>
where
    T: Zero + Add<Output = T> + Copy,
{
    type Item = T;
    fn add_assign(&mut self, rhs: &[Self::Item]) {
        if self.len() < rhs.len() {
            self.resize(rhs.len(), T::zero());
        }
        self.as_mut_slice().add_assign(rhs);
    }
}

pub trait ArraySub {
    type Item;
    fn sub(&self, rhs: &[Self::Item]) -> Vec<Self::Item>;
}

impl<T> ArraySub for [T]
where
    T: Zero + Sub<Output = T> + Copy,
{
    type Item = T;
    fn sub(&self, rhs: &[Self::Item]) -> Vec<Self::Item> {
        let mut c = vec![T::zero(); self.len().max(rhs.len())];
        c[..self.len()].copy_from_slice(self);
        c.sub_assign(rhs);
        c
    }
}

pub trait ArraySubAssign {
    type Item;
    fn sub_assign(&mut self, rhs: &[Self::Item]);
}

impl<T> ArraySubAssign for [T]
where
    T: Sub<Output = T> + Copy,
{
    type Item = T;
    fn sub_assign(&mut self, rhs: &[Self::Item]) {
        assert!(self.len() >= rhs.len());
        self.iter_mut().zip(rhs).for_each(|(x, a)| *x = *x - *a);
    }
}

impl<T> ArraySubAssign for Vec<T>
where
    T: Zero + Sub<Output = T> + Copy,
{
    type Item = T;
    fn sub_assign(&mut self, rhs: &[Self::Item]) {
        if self.len() < rhs.len() {
            self.resize(rhs.len(), T::zero());
        }
        self.as_mut_slice().sub_assign(rhs);
    }
}

pub trait ArrayDot {
    type Item;
    fn dot(&self, rhs: &[Self::Item]) -> Vec<Self::Item>;
}

impl<T> ArrayDot for [T]
where
    T: Mul<Output = T> + Copy,
{
    type Item = T;
    fn dot(&self, rhs: &[Self::Item]) -> Vec<Self::Item> {
        assert!(self.len() == rhs.len());
        self.iter().zip(rhs).map(|p| *p.0 * *p.1).collect()
    }
}

pub trait ArrayDotAssign {
    type Item;
    fn dot_assign(&mut self, rhs: &[Self::Item]);
}

impl<T> ArrayDotAssign for [T]
where
    T: MulAssign + Copy,
{
    type Item = T;
    fn dot_assign(&mut self, rhs: &[Self::Item]) {
        assert!(self.len() == rhs.len());
        self.iter_mut().zip(rhs).for_each(|(x, a)| *x *= *a);
    }
}

pub trait ArrayMul {
    type Item;
    fn mul(&self, rhs: &[Self::Item]) -> Vec<Self::Item>;
}

impl<T> ArrayMul for [T]
where
    T: Zero + Mul<Output = T> + Copy,
{
    type Item = T;
    fn mul(&self, rhs: &[Self::Item]) -> Vec<Self::Item> {
        if self.is_empty() || rhs.is_empty() {
            return vec![];
        }
        let mut res = vec![zero(); self.len() + rhs.len() - 1];
        for (i, a) in self.iter().enumerate() {
            for (c, b) in res[i..].iter_mut().zip(rhs) {
                *c = *c + *a * *b;
            }
        }
        res
    }
}

pub trait ArrayNTT {
    type Item;
    fn ntt(&mut self);
    fn intt(&mut self);
    fn multiply(&self, rhs: &[Self::Item]) -> Vec<Self::Item>;
}

impl<T> ArrayNTT for [ModInt<T>]
where
    T: NTTFriendly,
{
    type Item = ModInt<T>;
    fn ntt(&mut self) {
        let f = self;
        let n = f.len();
        assert!(n.count_ones() == 1);
        assert!(n <= T::order());
        let len = n.trailing_zeros() as usize;
        let mut es = [ModInt::zero(); 30];
        let mut ies = [ModInt::zero(); 30];
        let mut sum_e = [ModInt::zero(); 30];
        let cnt2 = T::order().trailing_zeros() as usize;
        let mut e = ModInt::new_unchecked(T::zeta());
        let mut ie = e.inv();
        for i in (2..=cnt2).rev() {
            es[i - 2] = e;
            ies[i - 2] = ie;
            e = e * e;
            ie = ie * ie;
        }
        let mut now = ModInt::one();
        for i in 0..(cnt2 - 1) {
            sum_e[i] = es[i] * now;
            now *= ies[i];
        }
        for ph in 1..=len {
            let p = 1 << (len - ph);
            let mut now = ModInt::one();
            for (i, f) in f.chunks_exact_mut(2 * p).enumerate() {
                let (x, y) = f.split_at_mut(p);
                for (x, y) in x.iter_mut().zip(y.iter_mut()) {
                    let l = *x;
                    let r = *y * now;
                    *x = l + r;
                    *y = l - r;
                }
                now *= sum_e[(!i).trailing_zeros() as usize];
            }
        }
    }
    fn intt(&mut self) {
        let f = self;
        let n = f.len();
        assert!(n.count_ones() == 1);
        assert!(n <= T::order());
        let len = n.trailing_zeros() as usize;
        let mut es = [ModInt::zero(); 30];
        let mut ies = [ModInt::zero(); 30];
        let mut sum_ie = [ModInt::zero(); 30];
        let cnt2 = T::order().trailing_zeros() as usize;
        let mut e = ModInt::new_unchecked(T::zeta());
        let mut ie = e.inv();
        for i in (2..=cnt2).rev() {
            es[i - 2] = e;
            ies[i - 2] = ie;
            e = e * e;
            ie = ie * ie;
        }
        let mut now = ModInt::one();
        for i in 0..(cnt2 - 1) {
            sum_ie[i] = ies[i] * now;
            now *= es[i];
        }
        for ph in (1..=len).rev() {
            let p = 1 << (len - ph);
            let mut inow = ModInt::one();
            for (i, f) in f.chunks_exact_mut(2 * p).enumerate() {
                let (x, y) = f.split_at_mut(p);
                for (x, y) in x.iter_mut().zip(y.iter_mut()) {
                    let l = *x;
                    let r = *y;
                    *x = l + r;
                    *y = (l - r) * inow;
                }
                inow *= sum_ie[(!i).trailing_zeros() as usize];
            }
        }
        let ik = ModInt::new_unchecked((T::modulo() + 1) >> 1).pow(len as u64);
        for f in f.iter_mut() {
            *f *= ik;
        }
    }
    fn multiply(&self, rhs: &[Self::Item]) -> Vec<Self::Item> {
        if self.len().min(rhs.len()) <= 32 {
            return self.mul(rhs);
        }
        let size = (self.len() + rhs.len() - 1).next_power_of_two();
        let mut f = vec![ModInt::zero(); size];
        let mut g = vec![ModInt::zero(); size];
        f[..self.len()].copy_from_slice(self);
        g[..rhs.len()].copy_from_slice(rhs);
        f.ntt();
        g.ntt();
        f.dot_assign(&g);
        f.intt();
        f.truncate(self.len() + rhs.len() - 1);
        f
    }
}

pub trait PolynomialOperation {
    type Item;
    fn eval(&self, x: Self::Item) -> Self::Item;
    fn derivative(&self) -> Vec<Self::Item>;
    fn integral(&self) -> Vec<Self::Item>;
}

impl<T: Modulo> PolynomialOperation for [ModInt<T>] {
    type Item = ModInt<T>;
    fn eval(&self, x: Self::Item) -> Self::Item {
        self.iter().rev().fold(ModInt::zero(), |s, a| s * x + *a)
    }
    fn derivative(&self) -> Vec<Self::Item> {
        if self.len() <= 1 {
            return vec![];
        }
        self[1..]
            .iter()
            .enumerate()
            .map(|(k, a)| ModInt::new_unchecked(k as u32 + 1) * *a)
            .collect()
    }
    fn integral(&self) -> Vec<Self::Item> {
        if self.is_empty() {
            return vec![];
        }
        let mut inv = vec![ModInt::one(); self.len() + 1];
        let mut mul = ModInt::zero();
        for i in 1..=self.len() {
            mul += ModInt::one();
            inv[i] = inv[i - 1] * mul;
        }
        let mut prod = inv[self.len()].inv();
        for i in (1..=self.len()).rev() {
            inv[i] = self[i - 1] * inv[i - 1] * prod;
            prod *= mul;
            mul -= ModInt::one();
        }
        inv[0] = ModInt::zero();
        inv
    }
}

pub trait FPSOperation {
    type Item;
    fn inverse(&self, n: usize) -> Vec<Self::Item>;
    fn log(&self, n: usize) -> Vec<Self::Item>;
    fn exp(&self, n: usize) -> Vec<Self::Item>;
}

impl<T: NTTFriendly> FPSOperation for [ModInt<T>] {
    type Item = ModInt<T>;
    fn inverse(&self, n: usize) -> Vec<Self::Item> {
        assert!(self.len() > 0 && !self[0].is_zero());
        let len = n.next_power_of_two();
        assert!(2 * len <= T::order());
        let mut b = vec![ModInt::zero(); n];
        b[0] = self[0].inv();
        let mut f = Vec::with_capacity(2 * len);
        let mut g = Vec::with_capacity(2 * len);
        let mut size = 1;
        while size < n {
            g.clear();
            g.extend(b.iter().take(size));
            g.resize(2 * size, ModInt::zero());
            f.clear();
            f.extend(self.iter().take(2 * size));
            f.resize(2 * size, ModInt::zero());
            f.ntt();
            g.ntt();
            f.dot_assign(&g);
            f.intt();
            f[..size].iter_mut().for_each(|f| *f = ModInt::zero());
            f.ntt();
            f.dot_assign(&g);
            f.intt();
            for (b, g) in b[size..].iter_mut().zip(&f[size..]) {
                *b = *b - *g;
            }
            size *= 2;
        }
        b
    }
    fn log(&self, n: usize) -> Vec<Self::Item> {
        assert!(self.get(0).map_or(false, |p| p.get() == 1));
        let mut b = self.derivative().multiply(&self.inverse(n));
        b.truncate(n - 1);
        let mut b = b.integral();
        b.resize(n, ModInt::zero());
        b
    }
    fn exp(&self, n: usize) -> Vec<Self::Item> {
        assert!(self.get(0).map_or(true, |a| a.is_zero()));
        assert!(n <= T::order());
        let mut b = vec![ModInt::one()];
        let mut size = 1;
        while size < n {
            size <<= 1;
            let f = b.log(size);
            let g = self[..self.len().min(size)].sub(&f);
            b = b.multiply(&g).add(&b);
            b.truncate(size);
        }
        b.truncate(n);
        b.resize(n, ModInt::zero());
        b
    }
}

// test
//  yuki907: https://yukicoder.me/submissions/712523
//  hhkb2020: https://atcoder.jp/contests/hhkb2020/submissions/26997806
//