結果
| 問題 | No.802 だいたい等差数列 |
| ユーザー |
 nebocco
|
| 提出日時 | 2021-02-24 20:26:41 |
| 言語 | Rust (1.83.0 + proconio) |
| 結果 |
AC
|
| 実行時間 | 43 ms / 2,000 ms |
| コード長 | 7,300 bytes |
| コンパイル時間 | 13,118 ms |
| コンパイル使用メモリ | 390,680 KB |
| 実行使用メモリ | 24,528 KB |
| 最終ジャッジ日時 | 2024-09-24 20:33:11 |
| 合計ジャッジ時間 | 14,693 ms |
|
ジャッジサーバーID （参考情報） |
judge2 / judge4 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 4 |
| other | AC * 30 |
ソースコード
fn main() {let mut io = IO::new();input!{ from io,n: usize, mut m: usize, d1: usize, d2: usize}if d1 * (n - 1) + 1 > m { io.println(0); return; }m -= d1 * (n - 1) + 1;const MOD: i64 = 1_000_000_007;let d = d2 - d1;let fact = Fact::new(m + n, MOD);let mut f = vec![0; n];for i in 0..n {if m < (d + 1) * i { break; }f[i] = fact.combination(n - 1, i) * fact.combination(m + n - (d + 1) * i, n) % MOD;}for i in (1..n).rev() {f[i-1] -= f[i];}io.println(f[0].rem_euclid(MOD));}// ------------ struct Fact start ------------pub struct Fact {modulo: i64,fact: Vec<i64>,inv_fact: Vec<i64>}impl Fact {pub fn new(size: usize, modulo: i64) -> Self {let mut fact = vec![1; size + 1];let mut inv_fact = vec![1; size + 1];for i in 1..size+1 {fact[i] = fact[i-1] * i as i64 % modulo;}inv_fact[size] = Self::modinv(fact[size], modulo);for i in (1..size+1).rev() {inv_fact[i-1] = inv_fact[i] * i as i64 % modulo;}Fact {modulo, fact, inv_fact}}pub fn extgcd(a: i64, b: i64) -> (i64, i64) {let mut x1 = 1;let mut y1 = 0;let mut m = a;let mut x2 = 0;let mut y2 = 1;let mut n = b;while m % n != 0 {let q = m / n;x1 -= q * x2;y1 -= q * y2;m -= q * n;std::mem::swap(&mut x1, &mut x2);std::mem::swap(&mut y1, &mut y2);std::mem::swap(&mut m, &mut n);}(x2, y2)}pub fn modinv(mut x: i64, modulo: i64) -> i64 {x = x.rem_euclid(modulo);Self::extgcd(x, modulo).0.rem_euclid(modulo)}pub fn permutation(&self, n:usize, r:usize) -> i64 {assert!(r > n || n < self.fact.len(),"index out of range: length is {}, but given {}", self.fact.len(), n);if n < r { return 0 };self.fact[n] * self.inv_fact[n-r] % self.modulo}pub fn combination(&self, n:usize, r:usize) -> i64 {assert!(r > n || n < self.fact.len(),"index out of range: length is {}, but given {}", self.fact.len(), n);if n < r { return 0 };self.fact[n] * self.inv_fact[r] % self.modulo * self.inv_fact[n-r] % self.modulo}pub fn multi(&self, l: &[usize]) -> i64 {let n = l.iter().sum::<usize>();assert!(n < self.fact.len(),"index out of range: length is {}, but given {}", self.fact.len(), n);let mut ans = self.fact[n];for &x in l {ans = ans * self.inv_fact[x] % self.modulo;}ans}}// ------------ struct Fact start ------------// ------------ io module start ------------use std::io::{stdout, BufWriter, Read, StdoutLock, Write};pub struct IO {iter: std::str::SplitAsciiWhitespace<'static>,buf: BufWriter<StdoutLock<'static>>,}impl IO {pub fn new() -> Self {let mut input = String::new();std::io::stdin().read_to_string(&mut input).unwrap();let input = Box::leak(input.into_boxed_str());let out = Box::new(stdout());IO {iter: input.split_ascii_whitespace(),buf: BufWriter::new(Box::leak(out).lock()),}}fn scan_str(&mut self) -> &'static str {self.iter.next().unwrap()}pub fn scan<T: Scan>(&mut self) -> <T as Scan>::Output {<T as Scan>::scan(self)}pub fn scan_vec<T: Scan>(&mut self, n: usize) -> Vec<<T as Scan>::Output> {(0..n).map(|_| self.scan::<T>()).collect()}pub fn print<T: Print>(&mut self, x: T) {<T as Print>::print(self, x);}pub fn println<T: Print>(&mut self, x: T) {self.print(x);self.print("\n");}pub fn iterln<T: Print, I: Iterator<Item = T>>(&mut self, mut iter: I, delim: &str) {if let Some(v) = iter.next() {self.print(v);for v in iter {self.print(delim);self.print(v);}}self.print("\n");}pub fn flush(&mut self) {self.buf.flush().unwrap();}}impl Default for IO {fn default() -> Self {Self::new()}}pub trait Scan {type Output;fn scan(io: &mut IO) -> Self::Output;}macro_rules! impl_scan {($($t:tt),*) => {$(impl Scan for $t {type Output = Self;fn scan(s: &mut IO) -> Self::Output {s.scan_str().parse().unwrap()}})*};}impl_scan!(i16, i32, i64, isize, u16, u32, u64, usize, String);pub enum Bytes {}impl Scan for Bytes {type Output = &'static [u8];fn scan(s: &mut IO) -> Self::Output {s.scan_str().as_bytes()}}pub enum Chars {}impl Scan for Chars {type Output = Vec<char>;fn scan(s: &mut IO) -> Self::Output {s.scan_str().chars().collect()}}pub enum Usize1 {}impl Scan for Usize1 {type Output = usize;fn scan(s: &mut IO) -> Self::Output {s.scan::<usize>().wrapping_sub(1)}}impl<T: Scan, U: Scan> Scan for (T, U) {type Output = (T::Output, U::Output);fn scan(s: &mut IO) -> Self::Output {(T::scan(s), U::scan(s))}}impl<T: Scan, U: Scan, V: Scan> Scan for (T, U, V) {type Output = (T::Output, U::Output, V::Output);fn scan(s: &mut IO) -> Self::Output {(T::scan(s), U::scan(s), V::scan(s))}}impl<T: Scan, U: Scan, V: Scan, W: Scan> Scan for (T, U, V, W) {type Output = (T::Output, U::Output, V::Output, W::Output);fn scan(s: &mut IO) -> Self::Output {(T::scan(s), U::scan(s), V::scan(s), W::scan(s))}}pub trait Print {fn print(w: &mut IO, x: Self);}macro_rules! impl_print_int {($($t:ty),*) => {$(impl Print for $t {fn print(w: &mut IO, x: Self) {w.buf.write_all(x.to_string().as_bytes()).unwrap();}})*};}impl_print_int!(i16, i32, i64, isize, u16, u32, u64, usize);impl Print for u8 {fn print(w: &mut IO, x: Self) {w.buf.write_all(&[x]).unwrap();}}impl Print for &[u8] {fn print(w: &mut IO, x: Self) {w.buf.write_all(x).unwrap();}}impl Print for &str {fn print(w: &mut IO, x: Self) {w.print(x.as_bytes());}}impl Print for String {fn print(w: &mut IO, x: Self) {w.print(x.as_bytes());}}impl<T: Print, U: Print> Print for (T, U) {fn print(w: &mut IO, (x, y): Self) {w.print(x);w.print(" ");w.print(y);}}impl<T: Print, U: Print, V: Print> Print for (T, U, V) {fn print(w: &mut IO, (x, y, z): Self) {w.print(x);w.print(" ");w.print(y);w.print(" ");w.print(z);}}mod neboccoio_macro {#[macro_export]macro_rules! input {(@start $io:tt @read @rest) => {};(@start $io:tt @read @rest, $($rest: tt)*) => {input!(@start $io @read @rest $($rest)*)};(@start $io:tt @read @rest mut $($rest:tt)*) => {input!(@start $io @read @mut [mut] @rest $($rest)*)};(@start $io:tt @read @rest $($rest:tt)*) => {input!(@start $io @read @mut [] @rest $($rest)*)};(@start $io:tt @read @mut [$($mut:tt)?] @rest $var:tt: [$kind:tt; $len:expr] $($rest:tt)*) => {let $($mut)* $var = $io.scan_vec::<$kind>($len);input!(@start $io @read @rest $($rest)*)};(@start $io:tt @read @mut [$($mut:tt)?] @rest $var:tt: $kind:tt $($rest:tt)*) => {let $($mut)* $var = $io.scan::<$kind>();input!(@start $io @read @rest $($rest)*)};(from $io:tt $($rest:tt)*) => {input!(@start $io @read @rest $($rest)*)};}}// ------------ io module end ------------