結果
問題 |
No.502 階乗を計算するだけ
|
ユーザー |
![]() |
提出日時 | 2025-06-25 21:08:59 |
言語 | Rust (1.83.0 + proconio) |
結果 |
AC
|
実行時間 | 34 ms / 1,000 ms |
コード長 | 32,896 bytes |
コンパイル時間 | 15,839 ms |
コンパイル使用メモリ | 400,456 KB |
実行使用メモリ | 7,844 KB |
最終ジャッジ日時 | 2025-06-25 21:09:18 |
合計ジャッジ時間 | 17,577 ms |
ジャッジサーバーID (参考情報) |
judge4 / judge2 |
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ファイルパターン | 結果 |
---|---|
other | AC * 52 |
コンパイルメッセージ
warning: method `join` is never used --> src/main.rs:995:12 | 994 | pub trait Join { | ---- method in this trait 995 | fn join(self, sep: &str) -> String; | ^^^^ | = note: `#[warn(dead_code)]` on by default
ソースコード
type M = ModInt<1_000_000_007>; fn main() { input! { n: usize, } println!("{}", factorial(n)); } fn factorial(n: usize) -> M { if n <= 1 { return M::one(); } if n >= 1_000_000_007 { return M::zero(); } let mut f = vec![M::one(), M::new(2)]; let mut k = 0; while (1 << (2 * k + 2)) <= n { let deg = 1 << k; let next = 2 * deg; f = shift_of_sampling_points_of_polynomial(&f, M::zero(), 2 * (next + 1)); f = f.chunks_exact(2).map(|f| f[0] * f[1]).collect(); k += 1; } let q = n >> k; let g = shift_of_sampling_points_of_polynomial(&f, M::zero(), q); let mut ans = g.iter().fold(M::one(), |s, a| s * *a); for i in (q << k)..n { ans *= M::from(i + 1); } ans } // ---------- begin input macro ---------- // reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8 #[macro_export] macro_rules! input { (source = $s:expr, $($r:tt)*) => { let mut iter = $s.split_whitespace(); input_inner!{iter, $($r)*} }; ($($r:tt)*) => { let s = { use std::io::Read; let mut s = String::new(); std::io::stdin().read_to_string(&mut s).unwrap(); s }; let mut iter = s.split_whitespace(); input_inner!{iter, $($r)*} }; } #[macro_export] macro_rules! input_inner { ($iter:expr) => {}; ($iter:expr, ) => {}; ($iter:expr, $var:ident : $t:tt $($r:tt)*) => { let $var = read_value!($iter, $t); input_inner!{$iter $($r)*} }; } #[macro_export] macro_rules! read_value { ($iter:expr, ( $($t:tt),* )) => { ( $(read_value!($iter, $t)),* ) }; ($iter:expr, [ $t:tt ; $len:expr ]) => { (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>() }; ($iter:expr, chars) => { read_value!($iter, String).chars().collect::<Vec<char>>() }; ($iter:expr, bytes) => { read_value!($iter, String).bytes().collect::<Vec<u8>>() }; ($iter:expr, usize1) => { read_value!($iter, usize) - 1 }; ($iter:expr, $t:ty) => { $iter.next().unwrap().parse::<$t>().expect("Parse error") }; } // ---------- end input macro ---------- // ---------- begin modint ---------- pub const fn pow_mod(mut r: u32, mut n: u32, m: u32) -> u32 { let mut t = 1; while n > 0 { if n & 1 == 1 { t = (t as u64 * r as u64 % m as u64) as u32; } r = (r as u64 * r as u64 % m as u64) as u32; n >>= 1; } t } pub const fn primitive_root(p: u32) -> u32 { let mut m = p - 1; let mut f = [1; 30]; let mut k = 0; let mut d = 2; while d * d <= m { if m % d == 0 { f[k] = d; k += 1; } while m % d == 0 { m /= d; } d += 1; } if m > 1 { f[k] = m; k += 1; } let mut g = 1; while g < p { let mut ok = true; let mut i = 0; while i < k { ok &= pow_mod(g, (p - 1) / f[i], p) > 1; i += 1; } if ok { break; } g += 1; } g } pub const fn is_prime(n: u32) -> bool { if n <= 1 { return false; } let mut d = 2; while d * d <= n { if n % d == 0 { return false; } d += 1; } true } #[derive(Clone, Copy, PartialEq, Eq)] pub struct ModInt<const M: u32>(u32); impl<const M: u32> ModInt<{ M }> { const REM: u32 = { let mut t = 1u32; let mut s = !M + 1; let mut n = !0u32 >> 2; while n > 0 { if n & 1 == 1 { t = t.wrapping_mul(s); } s = s.wrapping_mul(s); n >>= 1; } t }; const INI: u64 = ((1u128 << 64) % M as u128) as u64; const VALID: () = assert!(is_prime(M) && M % 2 == 1 && M < (1 << 30)); const PRIMITIVE_ROOT: u32 = primitive_root(M); const ORDER: usize = 1 << (M - 1).trailing_zeros(); const fn reduce(x: u64) -> u32 { let _ = Self::VALID; let b = (x as u32 * Self::REM) as u64; let t = x + b * M as u64; (t >> 32) as u32 } const fn multiply(a: u32, b: u32) -> u32 { Self::reduce(a as u64 * b as u64) } pub const fn new(v: u32) -> Self { Self(Self::reduce((v % M) as u64 * Self::INI)) } pub const fn const_mul(&self, rhs: Self) -> Self { Self(Self::multiply(self.0, rhs.0)) } pub const fn pow(&self, mut n: u64) -> Self { let mut t = Self::new(1); let mut r = *self; while n > 0 { if n & 1 == 1 { t = t.const_mul(r); } r = r.const_mul(r); n >>= 1; } t } pub const fn inv(&self) -> Self { assert!(self.0 != 0); self.pow(M as u64 - 2) } pub const fn get(&self) -> u32 { let mut res = Self::reduce(self.0 as u64); if res >= M { res -= M; } res } pub const fn zero() -> Self { Self::new(0) } pub const fn one() -> Self { Self::new(1) } } impl<const M: u32> Add for ModInt<{ M }> { type Output = Self; fn add(self, rhs: Self) -> Self::Output { let mut v = self.0 + rhs.0; if v >= 2 * M { v -= 2 * M; } Self(v) } } impl<const M: u32> Sub for ModInt<{ M }> { type Output = Self; fn sub(self, rhs: Self) -> Self::Output { let mut v = self.0 - rhs.0; if self.0 < rhs.0 { v += 2 * M; } Self(v) } } impl<const M: u32> Mul for ModInt<{ M }> { type Output = Self; fn mul(self, rhs: Self) -> Self::Output { self.const_mul(rhs) } } impl<const M: u32> Div for ModInt<{ M }> { type Output = Self; fn div(self, rhs: Self) -> Self::Output { self * rhs.inv() } } impl<const M: u32> AddAssign for ModInt<{ M }> { fn add_assign(&mut self, rhs: Self) { *self = *self + rhs; } } impl<const M: u32> SubAssign for ModInt<{ M }> { fn sub_assign(&mut self, rhs: Self) { *self = *self - rhs; } } impl<const M: u32> MulAssign for ModInt<{ M }> { fn mul_assign(&mut self, rhs: Self) { *self = *self * rhs; } } impl<const M: u32> DivAssign for ModInt<{ M }> { fn div_assign(&mut self, rhs: Self) { *self = *self / rhs; } } impl<const M: u32> Neg for ModInt<{ M }> { type Output = Self; fn neg(self) -> Self::Output { if self.0 == 0 { self } else { Self(2 * M - self.0) } } } impl<const M: u32> std::fmt::Display for ModInt<{ M }> { fn fmt<'a>(&self, f: &mut std::fmt::Formatter<'a>) -> std::fmt::Result { write!(f, "{}", self.get()) } } impl<const M: u32> std::fmt::Debug for ModInt<{ M }> { fn fmt<'a>(&self, f: &mut std::fmt::Formatter<'a>) -> std::fmt::Result { write!(f, "{}", self.get()) } } impl<const M: u32> std::str::FromStr for ModInt<{ M }> { type Err = std::num::ParseIntError; fn from_str(s: &str) -> Result<Self, Self::Err> { let val = s.parse::<u32>()?; Ok(ModInt::new(val)) } } impl<const M: u32> From<usize> for ModInt<{ M }> { fn from(val: usize) -> ModInt<{ M }> { ModInt::new((val % M as usize) as u32) } } impl<const M: u32> From<u64> for ModInt<{ M }> { fn from(val: u64) -> ModInt<{ M }> { ModInt::new((val % M as u64) as u32) } } impl<const M: u32> Into<usize> for ModInt<{ M }> { fn into(self) -> usize { self.get() as usize } } // ---------- end modint ---------- // ---------- begin precalc ---------- pub struct Precalc<T> { fact: Vec<T>, ifact: Vec<T>, inv: Vec<T>, } impl<T> Precalc<T> where T: Copy + Field, { pub fn new(size: usize) -> Self { let mut fact = vec![T::one(); size + 1]; let mut ifact = vec![T::one(); size + 1]; let mut inv = vec![T::one(); size + 1]; let mut mul = T::one(); for i in 2..=size { mul = mul + T::one(); fact[i] = fact[i - 1] * mul; } ifact[size] = T::one() / fact[size]; for i in (2..=size).rev() { inv[i] = ifact[i] * fact[i - 1]; ifact[i - 1] = ifact[i] * mul; mul = mul - T::one(); } Self { fact, ifact, inv } } pub fn fact(&self, n: usize) -> T { self.fact[n] } pub fn ifact(&self, n: usize) -> T { self.ifact[n] } pub fn inv(&self, n: usize) -> T { assert!(0 < n); self.inv[n] } pub fn perm(&self, n: usize, k: usize) -> T { if k > n { return T::zero(); } self.fact[n] * self.ifact[n - k] } pub fn binom(&self, n: usize, k: usize) -> T { if n < k { return T::zero(); } self.fact[n] * self.ifact[k] * self.ifact[n - k] } } // ---------- end precalc ---------- impl<const M: u32> Zero for ModInt<{ M }> { fn zero() -> Self { Self::zero() } fn is_zero(&self) -> bool { self.0 == 0 } } impl<const M: u32> One for ModInt<{ M }> { fn one() -> Self { Self::one() } fn is_one(&self) -> bool { self.get() == 1 } } // ---------- begin array op ---------- struct NTTPrecalc<const M: u32> { sum_e: [ModInt<{ M }>; 30], sum_ie: [ModInt<{ M }>; 30], } impl<const M: u32> NTTPrecalc<{ M }> { const fn new() -> Self { let cnt2 = (M - 1).trailing_zeros() as usize; let root = ModInt::new(ModInt::<{ M }>::PRIMITIVE_ROOT); let zeta = root.pow((M - 1) as u64 >> cnt2); let mut es = [ModInt::zero(); 30]; let mut ies = [ModInt::zero(); 30]; let mut sum_e = [ModInt::zero(); 30]; let mut sum_ie = [ModInt::zero(); 30]; let mut e = zeta; let mut ie = e.inv(); let mut i = cnt2; while i >= 2 { es[i - 2] = e; ies[i - 2] = ie; e = e.const_mul(e); ie = ie.const_mul(ie); i -= 1; } let mut now = ModInt::one(); let mut inow = ModInt::one(); let mut i = 0; while i < cnt2 - 1 { sum_e[i] = es[i].const_mul(now); sum_ie[i] = ies[i].const_mul(inow); now = ies[i].const_mul(now); inow = es[i].const_mul(inow); i += 1; } Self { sum_e, sum_ie } } } struct NTTPrecalcHelper<const MOD: u32>; impl<const MOD: u32> NTTPrecalcHelper<MOD> { const A: NTTPrecalc<MOD> = NTTPrecalc::new(); } 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 + One + 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![T::zero(); self.len() + rhs.len() - 1]; for (i, a) in self.iter().enumerate() { for (res, b) in res[i..].iter_mut().zip(rhs.iter()) { *res = *res + *a * *b; } } res } } pub trait NTT { fn ntt(&mut self); fn intt(&mut self); fn transform(&mut self, len: usize); fn inverse_transform(&mut self, len: usize); fn dot_product_ntt(&mut self, rhs: &Self, len: usize); } impl<const M: u32> NTT for [ModInt<{ M }>] { fn ntt(&mut self) { self.transform(1); } fn intt(&mut self) { self.inverse_transform(1); } fn transform(&mut self, len: usize) { let f = self; let n = f.len(); let k = (n / len).trailing_zeros() as usize; assert!(len << k == n); assert!(k <= ModInt::<{ M }>::ORDER); let pre = &NTTPrecalcHelper::<{ M }>::A; for ph in 1..=k { let p = len << (k - 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 *= pre.sum_e[(!i).trailing_zeros() as usize]; } } } fn inverse_transform(&mut self, len: usize) { let f = self; let n = f.len(); let k = (n / len).trailing_zeros() as usize; assert!(len << k == n); assert!(k <= ModInt::<{ M }>::ORDER); let pre = &NTTPrecalcHelper::<{ M }>::A; for ph in (1..=k).rev() { let p = len << (k - 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 *= pre.sum_ie[(!i).trailing_zeros() as usize]; } } let ik = ModInt::new(2).inv().pow(k as u64); for f in f.iter_mut() { *f *= ik; } } fn dot_product_ntt(&mut self, rhs: &Self, len: usize) { let mut buf = [ModInt::zero(); 20]; let buf = &mut buf[..(2 * len - 1)]; let pre = &NTTPrecalcHelper::<{ M }>::A; let mut now = ModInt::one(); for (i, (f, g)) in self .chunks_exact_mut(2 * len) .zip(rhs.chunks_exact(2 * len)) .enumerate() { let mut r = now; for (f, g) in f.chunks_exact_mut(len).zip(g.chunks_exact(len)) { buf.fill(ModInt::zero()); for (i, f) in f.iter().enumerate() { for (buf, g) in buf[i..].iter_mut().zip(g.iter()) { *buf = *buf + *f * *g; } } f.copy_from_slice(&buf[..len]); for (f, buf) in f.iter_mut().zip(buf[len..].iter()) { *f = *f + r * *buf; } r = -r; } now *= pre.sum_e[(!i).trailing_zeros() as usize]; } } } // transform でlen=1を指定すればNTTになる pub trait ArrayConvolution { type Item; fn convolution(&self, rhs: &[Self::Item]) -> Vec<Self::Item>; fn middle_product(&self, a: &[Self::Item]) -> Vec<Self::Item>; } pub fn convolution_modulo<const MOD: u32, const A: u32>( a: &[ModInt<MOD>], b: &[ModInt<MOD>], ) -> Vec<ModInt<A>> { let a = a .iter() .map(|a| ModInt::<A>::new(a.get())) .collect::<Vec<_>>(); let b = b .iter() .map(|a| ModInt::<A>::new(a.get())) .collect::<Vec<_>>(); a.convolution(&b) } pub fn middle_product_modulo<const MOD: u32, const A: u32>( a: &[ModInt<MOD>], b: &[ModInt<MOD>], ) -> Vec<ModInt<A>> { let a = a .iter() .map(|a| ModInt::<A>::new(a.get())) .collect::<Vec<_>>(); let b = b .iter() .map(|a| ModInt::<A>::new(a.get())) .collect::<Vec<_>>(); a.middle_product(&b) } impl<const M: u32> ArrayConvolution for [ModInt<{ M }>] { type Item = ModInt<{ M }>; fn convolution(&self, rhs: &[Self::Item]) -> Vec<Self::Item> { if self.len().min(rhs.len()) <= 32 { return self.mul(rhs); } const PARAM: usize = 10; let size = self.len() + rhs.len() - 1; let mut k = 0; while (size + (1 << k) - 1) >> k > PARAM { k += 1; } if ModInt::<{ M }>::ORDER < k { const A: u32 = 167772161; const B: u32 = 469762049; const C: u32 = 754974721; assert!(ModInt::<A>::ORDER >= k); assert!(ModInt::<B>::ORDER >= k); assert!(ModInt::<C>::ORDER >= k); const P: u32 = pow_mod(A, B - 2, B); const Q: u32 = pow_mod(A, C - 2, C); const R: u32 = pow_mod(B, C - 2, C); const QR: u32 = (Q as u64 * R as u64 % C as u64) as u32; const W1: u32 = A; let w2: u32 = (A as u64 * B as u64 % M as u64) as u32; let x: Vec<ModInt<A>> = convolution_modulo(self, rhs); let y: Vec<ModInt<B>> = convolution_modulo(self, rhs); let z: Vec<ModInt<C>> = convolution_modulo(self, rhs); let mut ans = vec![ModInt::<{ M }>::zero(); x.len()]; for (((ans, x), y), z) in ans.iter_mut().zip(x).zip(y).zip(z) { let a = x.get(); let b = ((y.get() + B - a) as u64 * P as u64 % B as u64) as u32; let c = (((z.get() + C - a) as u64 * QR as u64 + (C - b) as u64 * R as u64) % C as u64) as u32; *ans = (a as u64 + b as u64 * W1 as u64 + c as u64 * w2 as u64).into(); } return ans; } let len = (size + (1 << k) - 1) >> k; let mut f = vec![ModInt::zero(); len << k]; let mut g = vec![ModInt::zero(); len << k]; f[..self.len()].copy_from_slice(self); g[..rhs.len()].copy_from_slice(rhs); f.transform(len); g.transform(len); f.dot_product_ntt(&g, len); f.inverse_transform(len); f.truncate(self.len() + rhs.len() - 1); f } fn middle_product(&self, rhs: &[Self::Item]) -> Vec<Self::Item> { assert!(self.len() >= rhs.len()); if self.len() - rhs.len() <= 32 { return self .windows(rhs.len()) .map(|a| { a.iter() .zip(rhs.iter()) .fold(ModInt::zero(), |s, p| s + *p.0 * *p.1) }) .collect(); } const PARAM: usize = 10; let size = self.len(); let mut k = 0; while (size + (1 << k) - 1) >> k > PARAM { k += 1; } if ModInt::<{ M }>::ORDER < k { const A: u32 = 167772161; const B: u32 = 469762049; const C: u32 = 754974721; assert!(ModInt::<A>::ORDER >= k); assert!(ModInt::<B>::ORDER >= k); assert!(ModInt::<C>::ORDER >= k); const P: u32 = pow_mod(A, B - 2, B); const Q: u32 = pow_mod(A, C - 2, C); const R: u32 = pow_mod(B, C - 2, C); const QR: u32 = (Q as u64 * R as u64 % C as u64) as u32; const W1: u32 = A; let w2: u32 = (A as u64 * B as u64 % M as u64) as u32; let x: Vec<ModInt<A>> = middle_product_modulo(self, rhs); let y: Vec<ModInt<B>> = middle_product_modulo(self, rhs); let z: Vec<ModInt<C>> = middle_product_modulo(self, rhs); let mut ans = vec![ModInt::<{ M }>::zero(); x.len()]; for (((ans, x), y), z) in ans.iter_mut().zip(x).zip(y).zip(z) { let a = x.get(); let b = ((y.get() + B - a) as u64 * P as u64 % B as u64) as u32; let c = (((z.get() + C - a) as u64 * QR as u64 + (C - b) as u64 * R as u64) % C as u64) as u32; *ans = (a as u64 + b as u64 * W1 as u64 + c as u64 * w2 as u64).into(); } return ans; } let len = (size + (1 << k) - 1) >> k; let mut f = vec![ModInt::zero(); len << k]; let mut g = vec![ModInt::zero(); len << k]; f[..self.len()].copy_from_slice(self); g[..rhs.len()].copy_from_slice(rhs); g[..rhs.len()].reverse(); f.transform(len); g.transform(len); f.dot_product_ntt(&g, len); f.inverse_transform(len); (rhs.len()..=self.len()).map(|i| f[i - 1]).collect() } } 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> PolynomialOperation for [T] where T: Field + Copy, { type Item = T; fn eval(&self, x: Self::Item) -> Self::Item { self.iter().rfold(T::zero(), |s, a| s * x + *a) } fn derivative(&self) -> Vec<Self::Item> { if self.len() <= 1 { return vec![]; } self[1..] .iter() .scan(T::one(), |s, a| { let res = *a * *s; *s = *s + T::one(); Some(res) }) .collect() } fn integral(&self) -> Vec<Self::Item> { if self.is_empty() { return vec![]; } let mut inv = vec![T::one(); self.len() + 1]; let mut val = T::zero(); for i in 1..inv.len() { val = val + T::one(); inv[i] = val * inv[i - 1]; } let mut iprod = T::one() / inv[self.len()]; for i in (1..inv.len()).rev() { inv[i] = iprod * inv[i - 1] * self[i - 1]; iprod = iprod * val; val = val - T::one(); } inv[0] = T::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> FPSOperation for [T] where T: Field + Copy, [T]: ArrayConvolution<Item = T>, { type Item = T; fn inverse(&self, n: usize) -> Vec<Self::Item> { assert!(self.len() > 0 && !self[0].is_zero()); if n == 0 { return vec![]; } let mut g = Vec::with_capacity(n); g.push(T::one() / self[0]); while g.len() < n { let size = g.len(); let up = (2 * size).min(n); let gg = g.convolution(&g); let mut h = gg.convolution(&self[..up.min(self.len())]); h.resize(up, T::zero()); g.extend(h[size..up].iter().map(|v| -*v)); } g } fn log(&self, n: usize) -> Vec<Self::Item> { assert!(self.len() > 0 && self[0].is_one()); if n == 0 { return vec![]; } let mut res = self.derivative().convolution(&self.inverse(n)); res.truncate(n - 1); res.integral() } fn exp(&self, n: usize) -> Vec<Self::Item> { assert!(self.len() > 0 && self[0].is_zero()); if n == 0 { return vec![]; } let mut g = Vec::with_capacity(n); g.push(T::one()); while g.len() < n { let size = g.len(); let up = (2 * size).min(n); let lg = g.log(up); let rhs = self[..up.min(self.len())].sub(&lg); let mut h = g.convolution(&rhs); h.resize(up, T::zero()); g.extend(h[size..up].iter().cloned()); } g } } // ---------- end array op ---------- // ---------- begin trait ---------- use std::ops::*; pub trait Zero: Sized + Add<Self, Output = Self> { fn zero() -> Self; fn is_zero(&self) -> bool; } pub trait One: Sized + Mul<Self, Output = Self> { fn one() -> Self; fn is_one(&self) -> bool; } pub trait Group: Zero + Sub<Output = Self> + Neg<Output = Self> {} pub trait SemiRing: Zero + One {} pub trait Ring: SemiRing + Group {} pub trait Field: Ring + Div<Output = Self> {} impl<T> Group for T where T: Zero + Sub<Output = Self> + Neg<Output = Self> {} impl<T> SemiRing for T where T: Zero + One {} impl<T> Ring for T where T: SemiRing + Group {} impl<T> Field for T where T: Ring + Div<Output = Self> {} pub fn zero<T: Zero>() -> T { T::zero() } pub fn one<T: One>() -> T { T::one() } pub fn pow<T: One + Clone>(mut r: T, mut n: usize) -> T { let mut t = one(); while n > 0 { if n & 1 == 1 { t = t * r.clone(); } r = r.clone() * r; n >>= 1; } t } pub fn pow_sum<T: SemiRing + Clone>(r: T, n: usize) -> T { if n == 0 { T::zero() } else if n & 1 == 1 { T::one() + r.clone() * pow_sum(r, n - 1) } else { let a = T::one() + r.clone(); let b = r.clone() * r; a * pow_sum(b, n / 2) } } // ---------- end trait ---------- mod util { pub trait Join { fn join(self, sep: &str) -> String; } impl<T, I> Join for I where I: Iterator<Item = T>, T: std::fmt::Display, { fn join(self, sep: &str) -> String { let mut s = String::new(); use std::fmt::*; for (i, v) in self.enumerate() { if i > 0 { write!(&mut s, "{}", sep).ok(); } write!(&mut s, "{}", v).ok(); } s } } } // ---------- taylor shift ---------- // f(x) とcを受け取って f(x+c) を返す pub trait TaylorShift { type Item; fn taylor_shift(&self, c: Self::Item) -> Vec<Self::Item>; } impl<T> TaylorShift for [T] where T: Copy + Field, [T]: ArrayConvolution<Item = T>, { type Item = T; fn taylor_shift(&self, c: Self::Item) -> Vec<Self::Item> { if self.is_empty() || c.is_zero() { return Vec::from(self); } let mut fact = vec![T::one(); self.len()]; let mut val = T::zero(); for i in 1..fact.len() { val = val + T::one(); fact[i] = fact[i - 1] * val; } let mut ifact = vec![T::one(); self.len()]; ifact[self.len() - 1] = T::one() / fact[self.len() - 1]; for i in (1..fact.len()).rev() { ifact[i - 1] = ifact[i] * val; val = val - T::one(); } let mut a = Vec::from(self); for (a, f) in a.iter_mut().zip(fact.iter()) { *a = *a * *f; } a.reverse(); let mut pow = T::one(); for (f, i) in fact.iter_mut().zip(ifact.iter()) { *f = *i * pow; pow = pow * c; } a = a.convolution(&fact); a.truncate(self.len()); a.reverse(); for (a, i) in a.iter_mut().zip(ifact.iter()) { *a = *a * *i; } a } } // ---------- taylor shift ---------- // f(x) を x = a * r^i (0 <= i < m) で評価した値の列を返す pub fn multipoint_evaluation_on_geometric_sequence<T>(f: &[T], a: T, r: T, m: usize) -> Vec<T> where T: Copy + Field, [T]: ArrayConvolution<Item = T>, { let n = f.len(); assert!(n > 0 && m > 0); if r.is_zero() { let mut res = vec![f[0]; m]; res[0] = f.iter().rev().fold(T::zero(), |s, f| s * a + *f); return res; } let ir = T::one() / r; let mut f = Vec::from(f); let mut dp = (T::one(), ir); for f in f.iter_mut() { *f = *f * dp.0; dp = (dp.0 * dp.1 * a, dp.1 * ir); } let mut g = vec![T::zero(); n + m - 1]; let mut dp = (T::one(), r); for g in g.iter_mut() { *g = dp.0; dp = (dp.0 * dp.1, dp.1 * r); } f = g.middle_product(&f); let mut dp = (T::one(), ir); for f in f.iter_mut() { *f = *f * dp.0; dp = (dp.0 * dp.1, dp.1 * ir); } f } pub fn multipoint_evaluation<T>(c: Vec<T>, p: Vec<T>) -> Vec<T> where T: Copy + Field, [T]: ArrayConvolution<Item = T> + FPSOperation<Item = T>, { if p.is_empty() { return vec![]; } let n = c.len(); let m = p.len(); let mut prod = vec![vec![]; 2 * m]; for (prod, p) in prod[m..].iter_mut().zip(p.iter()) { *prod = vec![T::one(), -*p]; } for i in (1..m).rev() { prod[i] = prod[2 * i].convolution(&prod[2 * i + 1]); } let inv = prod[1].inverse(n); let mut c = c; c.resize(n + m - 1, T::zero()); let mut dp = vec![vec![]; 2 * m]; dp[1] = c.middle_product(&inv); for i in 1..m { dp[2 * i] = dp[i].middle_product(&prod[2 * i + 1]); dp[2 * i + 1] = dp[i].middle_product(&prod[2 * i]); } dp[m..].iter().map(|dp| dp[0]).collect() } pub fn shift_of_sampling_points_of_polynomial<T>(f: &[T], c: T, m: usize) -> Vec<T> where T: Copy + Field + From<usize> + Into<usize>, [T]: ArrayConvolution<Item = T>, { if f.is_empty() { return vec![T::zero(); m]; } if m == 0 { return vec![]; } let cv: usize = c.into(); if cv < f.len() { let sub = f.len() - cv; if m <= sub { return Vec::from(&f[cv..(cv + m)]); } let mut ans = Vec::from(&f[cv..]); ans.extend(shift_of_sampling_points_of_polynomial( &f, T::from(f.len()), m - sub, )); return ans; } for i in 0..m { if T::from(cv + i).is_zero() { let up = i; let mut ans = shift_of_sampling_points_of_polynomial(&f, c, up); ans.extend(&shift_of_sampling_points_of_polynomial( &f, T::zero(), m - up, )); return ans; } } let pc = Precalc::<T>::new(f.len()); let n = f.len(); let mut f = Vec::from(f); for (i, f) in f.iter_mut().enumerate() { *f = *f * pc.ifact(i) * pc.ifact(n - 1 - i); if (n - 1 - i) % 2 == 1 { *f = -*f; } } let mut prod = vec![one(); n + m - 1]; let mut v = T::one(); for i in 0..prod.len() { v = v * T::from(cv - (n - 1) + i); prod[i] = v; } let mut inv = vec![one(); n + m - 1]; inv[n + m - 2] = T::one() / prod[n + m - 2]; for i in (0..(inv.len() - 1)).rev() { inv[i] = inv[i + 1] * T::from(cv - (n - 1) + i + 1); inv[i + 1] = inv[i + 1] * prod[i]; } f.reverse(); let mut f = inv.middle_product(&f); let mut val = prod[n - 1]; for (i, f) in f.iter_mut().enumerate() { *f = *f * val; val = val * inv[i] * T::from(cv + 1 + i); } f }