結果
問題 | No.2747 Permutation Adjacent Sum |
ユーザー |
|
提出日時 | 2025-02-17 11:59:05 |
言語 | Rust (1.83.0 + proconio) |
結果 |
TLE
|
実行時間 | - |
コード長 | 30,939 bytes |
コンパイル時間 | 28,108 ms |
コンパイル使用メモリ | 400,940 KB |
実行使用メモリ | 252,640 KB |
最終ジャッジ日時 | 2025-02-17 11:59:42 |
合計ジャッジ時間 | 36,350 ms |
ジャッジサーバーID (参考情報) |
judge1 / judge4 |
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ファイルパターン | 結果 |
---|---|
sample | -- * 2 |
other | TLE * 1 -- * 39 |
ソースコード
use std::io::Read;fn get_word() -> String {let stdin = std::io::stdin();let mut stdin=stdin.lock();let mut u8b: [u8; 1] = [0];loop {let mut buf: Vec<u8> = Vec::with_capacity(16);loop {let res = stdin.read(&mut u8b);if res.unwrap_or(0) == 0 || u8b[0] <= b' ' {break;} else {buf.push(u8b[0]);}}if buf.len() >= 1 {let ret = String::from_utf8(buf).unwrap();return ret;}}}fn get<T: std::str::FromStr>() -> T { get_word().parse().ok().unwrap() }/// Verified by https://atcoder.jp/contests/abc198/submissions/21774342mod mod_int {use std::ops::*;pub trait Mod: Copy { fn m() -> i64; }#[derive(Copy, Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]pub struct ModInt<M> { pub x: i64, phantom: ::std::marker::PhantomData<M> }impl<M: Mod> ModInt<M> {// x >= 0pub fn new(x: i64) -> Self { ModInt::new_internal(x % M::m()) }fn new_internal(x: i64) -> Self {ModInt { x: x, phantom: ::std::marker::PhantomData }}pub fn pow(self, mut e: i64) -> Self {debug_assert!(e >= 0);let mut sum = ModInt::new_internal(1);let mut cur = self;while e > 0 {if e % 2 != 0 { sum *= cur; }cur *= cur;e /= 2;}sum}#[allow(dead_code)]pub fn inv(self) -> Self { self.pow(M::m() - 2) }}impl<M: Mod> Default for ModInt<M> {fn default() -> Self { Self::new_internal(0) }}impl<M: Mod, T: Into<ModInt<M>>> Add<T> for ModInt<M> {type Output = Self;fn add(self, other: T) -> Self {let other = other.into();let mut sum = self.x + other.x;if sum >= M::m() { sum -= M::m(); }ModInt::new_internal(sum)}}impl<M: Mod, T: Into<ModInt<M>>> Sub<T> for ModInt<M> {type Output = Self;fn sub(self, other: T) -> Self {let other = other.into();let mut sum = self.x - other.x;if sum < 0 { sum += M::m(); }ModInt::new_internal(sum)}}impl<M: Mod, T: Into<ModInt<M>>> Mul<T> for ModInt<M> {type Output = Self;fn mul(self, other: T) -> Self { ModInt::new(self.x * other.into().x % M::m()) }}impl<M: Mod, T: Into<ModInt<M>>> AddAssign<T> for ModInt<M> {fn add_assign(&mut self, other: T) { *self = *self + other; }}impl<M: Mod, T: Into<ModInt<M>>> SubAssign<T> for ModInt<M> {fn sub_assign(&mut self, other: T) { *self = *self - other; }}impl<M: Mod, T: Into<ModInt<M>>> MulAssign<T> for ModInt<M> {fn mul_assign(&mut self, other: T) { *self = *self * other; }}impl<M: Mod> Neg for ModInt<M> {type Output = Self;fn neg(self) -> Self { ModInt::new(0) - self }}impl<M> ::std::fmt::Display for ModInt<M> {fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {self.x.fmt(f)}}impl<M: Mod> ::std::fmt::Debug for ModInt<M> {fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {let (mut a, mut b, _) = red(self.x, M::m());if b < 0 {a = -a;b = -b;}write!(f, "{}/{}", a, b)}}impl<M: Mod> From<i64> for ModInt<M> {fn from(x: i64) -> Self { Self::new(x) }}// Finds the simplest fraction x/y congruent to r mod p.// The return value (x, y, z) satisfies x = y * r + z * p.fn red(r: i64, p: i64) -> (i64, i64, i64) {if r.abs() <= 10000 {return (r, 1, 0);}let mut nxt_r = p % r;let mut q = p / r;if 2 * nxt_r >= r {nxt_r -= r;q += 1;}if 2 * nxt_r <= -r {nxt_r += r;q -= 1;}let (x, z, y) = red(nxt_r, r);(x, y - q * z, z)}} // mod mod_intmacro_rules! define_mod {($struct_name: ident, $modulo: expr) => {#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]pub struct $struct_name {}impl mod_int::Mod for $struct_name { fn m() -> i64 { $modulo } }}}const MOD: i64 = 998_244_353;define_mod!(P, MOD);type MInt = mod_int::ModInt<P>;// FFT (in-place, verified as NTT only)// R: Ring + Copy// Verified by: https://judge.yosupo.jp/submission/53831// Adopts the technique used in https://judge.yosupo.jp/submission/3153.mod fft {use std::ops::*;// n should be a power of 2. zeta is a primitive n-th root of unity.// one is unity// Note that the result is bit-reversed.pub fn fft<R>(f: &mut [R], zeta: R, one: R)where R: Copy +Add<Output = R> +Sub<Output = R> +Mul<Output = R> {let n = f.len();assert!(n.is_power_of_two());let mut m = n;let mut base = zeta;unsafe {while m > 2 {m >>= 1;let mut r = 0;while r < n {let mut w = one;for s in r..r + m {let &u = f.get_unchecked(s);let d = *f.get_unchecked(s + m);*f.get_unchecked_mut(s) = u + d;*f.get_unchecked_mut(s + m) = w * (u - d);w = w * base;}r += 2 * m;}base = base * base;}if m > 1 {// m = 1let mut r = 0;while r < n {let &u = f.get_unchecked(r);let d = *f.get_unchecked(r + 1);*f.get_unchecked_mut(r) = u + d;*f.get_unchecked_mut(r + 1) = u - d;r += 2;}}}}pub fn inv_fft<R>(f: &mut [R], zeta_inv: R, one: R)where R: Copy +Add<Output = R> +Sub<Output = R> +Mul<Output = R> {let n = f.len();assert!(n.is_power_of_two());let zeta = zeta_inv; // inverse FFTlet mut zetapow = Vec::with_capacity(20);{let mut m = 1;let mut cur = zeta;while m < n {zetapow.push(cur);cur = cur * cur;m *= 2;}}let mut m = 1;unsafe {if m < n {zetapow.pop();let mut r = 0;while r < n {let &u = f.get_unchecked(r);let d = *f.get_unchecked(r + 1);*f.get_unchecked_mut(r) = u + d;*f.get_unchecked_mut(r + 1) = u - d;r += 2;}m = 2;}while m < n {let base = zetapow.pop().unwrap();let mut r = 0;while r < n {let mut w = one;for s in r..r + m {let &u = f.get_unchecked(s);let d = *f.get_unchecked(s + m) * w;*f.get_unchecked_mut(s) = u + d;*f.get_unchecked_mut(s + m) = u - d;w = w * base;}r += 2 * m;}m *= 2;}}}}// Depends on: fft.rs, MInt.rs// Verified by: ABC269-Ex (https://atcoder.jp/contests/abc269/submissions/39116328)pub struct FPSOps<M: mod_int::Mod = P> {gen: mod_int::ModInt<M>,}impl<M: mod_int::Mod> FPSOps<M> {pub fn new(gen: mod_int::ModInt<M>) -> Self {FPSOps { gen: gen }}}impl<M: mod_int::Mod> FPSOps<M> {pub fn add(&self, mut a: Vec<mod_int::ModInt<M>>, mut b: Vec<mod_int::ModInt<M>>) -> Vec<mod_int::ModInt<M>> {if a.len() < b.len() {std::mem::swap(&mut a, &mut b);}for i in 0..b.len() {a[i] += b[i];}a}pub fn mul(&self, a: Vec<mod_int::ModInt<M>>, b: Vec<mod_int::ModInt<M>>) -> Vec<mod_int::ModInt<M>> {type MInt<M> = mod_int::ModInt<M>;let n = a.len() - 1;let m = b.len() - 1;let mut p = 1;while p <= n + m { p *= 2; }let mut f = vec![MInt::new(0); p];let mut g = vec![MInt::new(0); p];for i in 0..n + 1 { f[i] = a[i]; }for i in 0..m + 1 { g[i] = b[i]; }let fac = MInt::new(p as i64).inv();let zeta = self.gen.pow((M::m() - 1) / p as i64);fft::fft(&mut f, zeta, 1.into());fft::fft(&mut g, zeta, 1.into());for i in 0..p { f[i] *= g[i] * fac; }fft::inv_fft(&mut f, zeta.inv(), 1.into());f.truncate(n + m + 1);f}}// Computes f^{-1} mod x^{f.len()}.// Reference: https://codeforces.com/blog/entry/56422// Complexity: O(n log n)// Verified by: https://judge.yosupo.jp/submission/3219// Depends on: MInt.rs, fft.rsfn fps_inv<P: mod_int::Mod + PartialEq>(f: &[mod_int::ModInt<P>],gen: mod_int::ModInt<P>) -> Vec<mod_int::ModInt<P>> {let n = f.len();assert!(n.is_power_of_two());assert_eq!(f[0], 1.into());let mut sz = 1;let mut r = vec![mod_int::ModInt::new(0); n];let mut tmp_f = vec![mod_int::ModInt::new(0); n];let mut tmp_r = vec![mod_int::ModInt::new(0); n];r[0] = 1.into();// Adopts the technique used in https://judge.yosupo.jp/submission/3153while sz < n {let zeta = gen.pow((P::m() - 1) / sz as i64 / 2);tmp_f[..2 * sz].copy_from_slice(&f[..2 * sz]);tmp_r[..2 * sz].copy_from_slice(&r[..2 * sz]);fft::fft(&mut tmp_r[..2 * sz], zeta, 1.into());fft::fft(&mut tmp_f[..2 * sz], zeta, 1.into());let fac = mod_int::ModInt::new(2 * sz as i64).inv().pow(2);for i in 0..2 * sz {tmp_f[i] *= tmp_r[i];}fft::inv_fft(&mut tmp_f[..2 * sz], zeta.inv(), 1.into());for v in &mut tmp_f[..sz] {*v = 0.into();}fft::fft(&mut tmp_f[..2 * sz], zeta, 1.into());for i in 0..2 * sz {tmp_f[i] = -tmp_f[i] * tmp_r[i] * fac;}fft::inv_fft(&mut tmp_f[..2 * sz], zeta.inv(), 1.into());r[sz..2 * sz].copy_from_slice(&tmp_f[sz..2 * sz]);sz *= 2;}r}type M = MInt;// Copied and modified from https://judge.yosupo.jp/submission/133199.// Originally by sansen.fn middle_product(c: &[M], a: &[M]) -> Vec<M> {assert!(c.len() >= a.len());if a.len() <= (1 << 5) {return c.windows(a.len()).map(|c| {c.iter().zip(a.iter()).fold(MInt::new(0), |s, a| s + *a.0 * *a.1)}).collect();}let size = c.len().next_power_of_two();let mut x = Vec::from(c);x.resize(size, MInt::new(0));let mut y = Vec::from(a);y.reverse();y.resize(size, MInt::new(0));let zeta = MInt::new(3).pow((MOD - 1) / size as i64);fft::fft(&mut x, zeta, 1.into());fft::fft(&mut y, zeta, 1.into());let factor = MInt::new(size as i64).inv();for i in 0..size {x[i] *= y[i] * factor;}fft::inv_fft(&mut x, zeta.inv(), 1.into());(a.len()..=c.len()).map(|z| x[z - 1]).collect()}fn multipoint_evaluation(ops: &FPSOps, c: &[MInt], p: &[MInt]) -> Vec<M> {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![MInt::new(1), -*p];}for i in (1..m).rev() {prod[i] = ops.mul(prod[2 * i].clone(), prod[2 * i + 1].clone());}let mut prod1 = prod[1].clone();let mut sz = 1;while sz < n { sz *= 2; }prod1.resize(sz, 0.into());let mut inv = fps_inv(&prod1, 3.into());inv.truncate(n);let mut c = c.to_vec();c.resize(n + m - 1, MInt::new(0));let mut dp = vec![vec![]; 2 * m];dp[1] = middle_product(&c, &inv);for i in 1..m {dp[2 * i] = middle_product(&dp[i], &prod[2 * i + 1]);dp[2 * i + 1] = middle_product(&dp[i], &prod[2 * i]);}dp[m..].iter().map(|dp| dp[0]).collect()}// End of copy-pasted part.fn fps_mul_all(ops: &FPSOps, f: &[Vec<MInt>]) -> Vec<MInt> {let m = f.len();let mut seg = vec![vec![]; 2 * m];for i in 0..m {seg[i + m] = f[i].to_vec();}for i in (1..m).rev() {seg[i] = ops.mul(std::mem::replace(&mut seg[2 * i], vec![]),std::mem::replace(&mut seg[2 * i + 1], vec![]),);}std::mem::replace(&mut seg[1], vec![])}fn fps_common_denom(ops: &FPSOps, frac: &[(Vec<MInt>, Vec<MInt>)]) -> (Vec<MInt>, Vec<MInt>) {let m = frac.len();let mut seg = vec![(vec![], vec![]); 2 * m];for i in 0..m {seg[i + m] = frac[i].clone();}for i in (1..m).rev() {let den = ops.mul(seg[2 * i].1.clone(), seg[2 * i + 1].1.clone());let mut num = ops.mul(std::mem::replace(&mut seg[2 * i].1, vec![]),std::mem::replace(&mut seg[2 * i + 1].0, vec![]),);let tmp = ops.mul(std::mem::replace(&mut seg[2 * i].0, vec![]),std::mem::replace(&mut seg[2 * i + 1].1, vec![]),);num = ops.add(num, tmp);seg[i] = (num, den);}std::mem::replace(&mut seg[1], (vec![], vec![]))}// https://37zigen.com/lagrange-interpolation/fn lagrange_interpolate(ops: &FPSOps, xy: &[(MInt, MInt)]) -> Vec<MInt> {let n = xy.len();let mut xs = vec![MInt::new(0); n];let mut ps = vec![vec![]; n];for i in 0..n {xs[i] = xy[i].0;ps[i] = vec![-xy[i].0, 1.into()];}let g = fps_mul_all(ops, &ps);let mut gdash = vec![MInt::new(0); n];for i in 0..n {gdash[i] = g[i + 1] * (i + 1) as i64;}let vals = multipoint_evaluation(ops, &gdash, &xs);let mut fracs = vec![(vec![MInt::new(1)], vec![]); n];for i in 0..n {fracs[i].0[0] = vals[i].inv() * xy[i].1;fracs[i].1 = vec![-xy[i].0, 1.into()];}let (num, _) = fps_common_denom(ops, &fracs);num}// Generated by 2747-helper.rsconst STEP: usize = 1000000;const LEN: usize = 1000;const FACT_TABLE: [i64; 1000] = [1,373341033,45596018,834980587,623627864,428937595,442819817,499710224,833655840,83857087,295201906,788488293,671639287,849315549,597398273,813259672,732727656,244038325,122642896,310517972,160030060,483239722,683879839,712910418,384710263,433880730,844360005,513089677,101492974,959253371,957629942,678615452,34035221,56734233,524027922,31729117,102311167,330331487,8332991,832392662,545208507,594075875,318497156,859275605,300738984,767818091,864118508,878131539,316588744,812496962,213689172,584871249,980836133,54096741,417876813,363266670,335481797,730839588,393495668,435793297,760025067,811438469,720976283,650770098,586537547,117371703,566486504,749562308,708205284,932912293,939830261,983699513,206579820,301188781,593164676,770845925,247687458,41047791,266419267,937835947,506268060,6177705,936268003,166873118,443834893,328979964,470135404,954410105,117565665,832761782,39806322,478922755,394880724,821825588,468705875,512554988,232240472,876497899,356048018,895187265,808258749,575505950,68190615,939065335,552199946,694814243,385460530,529769387,640377761,916128300,440133909,362216114,826373774,502324157,457648395,385510728,904737188,78988746,454565719,623828097,686156489,713476044,63602402,570334625,681055904,222059821,477211096,343363294,833792655,461853093,741797144,74731896,930484262,268372735,941222802,677432735,474842829,700451655,400176109,697644778,390377694,790010794,360642718,505712943,946647976,339045014,715797300,251680896,70091750,40517433,12629586,850635539,110877109,571935891,695965747,634938288,69072133,155093216,749696762,963086402,544711799,724471925,334646013,574791029,722417626,377929821,743946412,988034679,405207112,18063742,104121967,638607426,607304611,751377777,35834555,313632531,18058363,656121134,40763559,562910912,495867250,48767038,210864657,659137294,715390025,865854329,324322857,388911184,286059202,636456178,421290700,832276048,726437551,526417714,252522639,386147469,674313019,274769381,226519400,272047186,117153405,712896591,486826649,119444874,338909703,18536028,41814114,245606459,140617938,250512392,57084755,157807456,261113192,40258068,194807105,325341339,884328111,896332013,880836012,737358206,202713771,785454372,399586250,485457499,640827004,546969497,749602473,159788463,159111724,218592929,675932866,314795475,811539323,246883213,696818315,759880589,4302336,353070689,477909706,559289160,79781699,878094972,840903973,367416824,973366814,848259019,462421750,667227759,897917455,81800722,956276337,942686845,420541799,417005912,272641764,941778993,217214373,192220616,267901132,50530621,652678397,354880856,164289049,781023184,105376215,315094878,607856504,733905911,457743498,992735713,35212756,231822660,276036750,734558079,424180850,433186147,308380947,18333316,12935086,351491725,655645460,535812389,521902115,67016984,48682076,64748124,489360447,361275315,786336279,805161272,468129309,645091350,887284732,913004502,358814684,281295633,328970139,395955130,164840186,820902807,761699708,246274415,592331769,913846362,866682684,600130702,903837674,529462989,90612675,526540127,533047427,110008879,674279751,801920753,645226926,676886948,752481486,474034007,457790341,166813684,287671032,188118664,244731384,404032157,269766986,423996017,182948540,356801634,737863144,652014069,206068022,504569410,919894484,593398649,963768176,882517476,702523597,949028249,128957299,171997372,50865043,20937461,690959202,581356488,369182214,993580422,193500140,540665426,365786018,743731625,144980423,979536721,773259009,617053935,247670131,843705280,30419459,985463402,261585206,237885042,111276893,488166208,137660292,720784236,244467770,26368504,792857103,666885724,670313309,905683034,259415897,512017253,826265493,111960112,633652060,918048438,516432938,386972415,996212724,610073831,444094191,72480267,665038087,11584804,301029012,723617861,113763819,778259899,937766095,535448641,593907889,783573565,673298635,599533244,655712590,173350007,868198597,169013813,585161712,697502214,573994984,285943986,675831407,3134056,965907646,401920943,665949756,236277883,612745912,813282113,892454686,901222267,624900982,927122298,686321335,84924870,927606072,506664166,353631992,165913238,566073550,816674343,864877926,171259407,908752311,874007723,803597299,613676466,880336545,282280109,128761001,58852065,474075900,434816091,364856903,149123648,388854780,314693916,423183826,419733481,888483202,238933227,336564048,757103493,100189123,855479832,51370348,403061033,496971759,831753030,251718753,272779384,683379259,488844621,881783783,659478190,445719559,740782647,546525906,985524427,548033568,333772553,331916427,752533273,730387628,93829695,655989476,930661318,334885743,466041862,428105027,888238707,232218076,769865249,730641039,616996159,231721356,326973501,426068899,722403656,742756734,663270261,364187931,350431704,671823672,633125919,226166717,386814657,237594135,451479365,546182474,119366536,465211069,605313606,728508871,249619035,663053607,900453742,48293872,229958401,62402409,69570431,71921532,960467929,537087913,514588945,5138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https://yukicoder.me/problems/no/2747 (3.5)// solved with hints// \sum_{1 <= i <= N} (N-i)i^K が計算できれば良い。これはベルヌーイ数の先頭 K 項が O(K log K)-time 程度で計算できれば計算できる。// -> 解説を見た。ラグランジュ補間の方が簡単。最終的な多項式は K+2 次なので、0 <= i <= K+2 の K+3 点で補間する。// 最後に (N-2)! * (N-1) * 2 を掛けること。// - (N-2)!: 残りの点の埋め方// - (N-1): どの隙間を見るか// - 2: 左の方が大きいか// Tags: lagrange-polynomial-interpolation, lagrange-interpolationfn main() {let n: i64 = get();let k: i64 = get();let ops = FPSOps {gen: 3.into(),};let mut xy = vec![];let mut sum = MInt::new(0);for i in 0..k + 3 {sum += MInt::new(i).pow(k) * (n - i);xy.push((MInt::new(i), sum));}let p = lagrange_interpolate(&ops, &xy);let mut ans = MInt::new(0);let mut cur = MInt::new(1);for elem in p {ans += elem * cur;cur *= n;}ans *= 2;let tbl_idx = ((n - 1) as usize / STEP).min(LEN - 1);let mut fac = MInt::new(FACT_TABLE[tbl_idx]);for i in tbl_idx * STEP + 1..=(n - 1) as usize {fac *= i as i64;}ans *= fac;println!("{ans}");}