結果
問題 |
No.1044 正直者大学
|
ユーザー |
![]() |
提出日時 | 2020-05-01 21:59:47 |
言語 | Rust (1.83.0 + proconio) |
結果 |
AC
|
実行時間 | 10 ms / 2,000 ms |
コード長 | 5,115 bytes |
コンパイル時間 | 14,145 ms |
コンパイル使用メモリ | 378,688 KB |
実行使用メモリ | 6,656 KB |
最終ジャッジ日時 | 2024-12-25 06:30:26 |
合計ジャッジ時間 | 15,614 ms |
ジャッジサーバーID (参考情報) |
judge4 / judge1 |
(要ログイン)
ファイルパターン | 結果 |
---|---|
sample | AC * 2 |
other | AC * 28 |
ソースコード
// ---------- begin ModInt ----------const MOD: u32 = 1_000_000_007;#[derive(Clone, Copy)]struct ModInt(u32);impl std::ops::Add for ModInt {type Output = ModInt;fn add(self, rhs: ModInt) -> Self::Output {let mut d = self.0 + rhs.0;if d >= MOD {d -= MOD;}ModInt(d)}}impl std::ops::AddAssign for ModInt {fn add_assign(&mut self, rhs: ModInt) {*self = *self + rhs;}}impl std::ops::Sub for ModInt {type Output = ModInt;fn sub(self, rhs: ModInt) -> Self::Output {let mut d = self.0 + MOD - rhs.0;if d >= MOD {d -= MOD;}ModInt(d)}}impl std::ops::SubAssign for ModInt {fn sub_assign(&mut self, rhs: ModInt) {*self = *self - rhs;}}impl std::ops::Mul for ModInt {type Output = ModInt;fn mul(self, rhs: ModInt) -> Self::Output {ModInt((self.0 as u64 * rhs.0 as u64 % MOD as u64) as u32)}}impl std::ops::MulAssign for ModInt {fn mul_assign(&mut self, rhs: ModInt) {*self = *self * rhs;}}impl std::ops::Neg for ModInt {type Output = ModInt;fn neg(self) -> Self::Output {ModInt(if self.0 == 0 {0} else {MOD - self.0})}}impl std::fmt::Display for ModInt {fn fmt<'a>(&self, f: &mut std::fmt::Formatter<'a>) -> std::fmt::Result {write!(f, "{}", self.0)}}impl std::str::FromStr for ModInt {type Err = std::num::ParseIntError;fn from_str(s: &str) -> Result<Self, Self::Err> {let val = s.parse::<u32>()?;Ok(ModInt::new(val))}}impl From<usize> for ModInt {fn from(val: usize) -> ModInt {ModInt((val % MOD as usize) as u32)}}#[allow(dead_code)]impl ModInt {pub fn new(n: u32) -> ModInt {ModInt(n % MOD)}pub fn zero() -> ModInt {ModInt(0)}pub fn one() -> ModInt {ModInt(1)}pub fn pow(self, mut n: u32) -> ModInt {let mut t = ModInt::one();let mut s = self;while n > 0 {if n & 1 == 1 {t *= s;}s *= s;n >>= 1;}t}pub fn inv(self) -> ModInt {assert!(self.0 > 0);self.pow(MOD - 2)}}// ---------- end ModInt ----------// ---------- begin Precalc ----------#[allow(dead_code)]struct Precalc {inv: Vec<ModInt>,fact: Vec<ModInt>,ifact: Vec<ModInt>,}#[allow(dead_code)]impl Precalc {pub fn new(n: usize) -> Precalc {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) {inv[i] = -inv[MOD as usize % i] * ModInt(MOD / i as u32);fact[i] = fact[i - 1] * ModInt(i as u32);ifact[i] = ifact[i - 1] * inv[i];}Precalc {inv: inv,fact: fact,ifact: ifact,}}pub fn inv(&self, n: usize) -> ModInt {self.inv[n]}pub fn fact(&self, n: usize) -> ModInt {self.fact[n]}pub fn ifact(&self, n: usize) -> ModInt {self.ifact[n]}pub fn comb(&self, n: usize, k: usize) -> ModInt {if k > n {return ModInt::zero();}self.fact[n] * self.ifact[k] * self.ifact[n - k]}}// ---------- end Precalc ----------//https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8 より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_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_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, usize1) => {read_value!($iter, usize) - 1};($iter:expr, $t:ty) => {$iter.next().unwrap().parse::<$t>().expect("Parse error")};}//fn run() {input! {n: usize,m: usize,k: usize,}let pc = Precalc::new(2 * (m + n));let mut ans = ModInt::zero();for i in 1.. {if n < i || m - 1 < i - 1 || n - i + m - i < k {break;}ans += pc.fact(n - 1) * pc.fact(m) * pc.comb(n - i + i, i) * pc.comb(m - 1, i - 1);}println!("{}", ans);}fn main() {run();}