#661182 (Rust) No.1518 Simple Combinatorics

• 問題: No.1518 Simple Combinatorics
• ユーザー: cotton_fn_
• 提出日時: 2021-05-28 21:06:30
• 言語: Rust (1.77.0 + proconio)
• 結果: AC
• 実行時間: 1 ms / 2,000 ms
• コード長: 13,992 bytes
• コンパイル時間: 18,648 ms
• コンパイル使用メモリ: 379,228 KB
• 実行使用メモリ: 5,248 KB
• 最終ジャッジ日時: 2024-11-07 08:37:51
• 合計ジャッジ時間: 14,725 ms
• ジャッジサーバーID （参考情報）: judge3 / judge1

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	1 ms; 5,248 KB
testcase_01	AC	1 ms; 5,248 KB
testcase_02	AC	1 ms; 5,248 KB
testcase_03	AC	1 ms; 5,248 KB
testcase_04	AC	1 ms; 5,248 KB
testcase_05	AC	1 ms; 5,248 KB
testcase_06	AC	1 ms; 5,248 KB
testcase_07	AC	1 ms; 5,248 KB
testcase_08	AC	1 ms; 5,248 KB
testcase_09	AC	1 ms; 5,248 KB
testcase_10	AC	1 ms; 5,248 KB
testcase_11	AC	1 ms; 5,248 KB
testcase_12	AC	1 ms; 5,248 KB
testcase_13	AC	1 ms; 5,248 KB
testcase_14	AC	1 ms; 5,248 KB
testcase_15	AC	1 ms; 5,248 KB
testcase_16	AC	1 ms; 5,248 KB
testcase_17	AC	1 ms; 5,248 KB
testcase_18	AC	1 ms; 5,248 KB
testcase_19	AC	1 ms; 5,248 KB
testcase_20	AC	1 ms; 5,248 KB
testcase_21	AC	1 ms; 5,248 KB

ソースコード

#![allow(unused_imports, unused_macros)]

use kyoproio::*;
use std::{
    collections::*,
    hash::Hash,
    io::{self, prelude::*},
    iter, mem,
};

fn run<I: Input, O: Write>(mut kin: I, mut out: O) {
    let (n, k): (u32, u32) = kin.parse();
    let a = (mint(1) - mint(n).inv()).pow(k);
    let e = mint(n) - mint(n) * a;
    let ans = mint(n).pow(k) * e;
    wln!(out, "{}", ans);
}

use std::{cmp, fmt, marker::PhantomData, ops, sync::atomic};
pub type Mint = ModInt<Mod1000000007>;
pub fn mint(x: u32) -> Mint {
    ModInt::new(x)
}
pub trait Modulo {
    fn modulo() -> u32;
}
macro_rules! modulo_impl {
    ($($Type:ident $val:tt)*) => {
        $(pub struct $Type;
        impl Modulo for $Type {
            fn modulo() -> u32 {
                $val
            }
        })*
    };
}
modulo_impl!(Mod998244353 998244353 Mod1000000007 1000000007);
pub struct VarMod;
static VAR_MOD: atomic::AtomicU32 = atomic::AtomicU32::new(0);
pub fn set_var_mod(m: u32) {
    VAR_MOD.store(m, atomic::Ordering::Relaxed);
}
impl Modulo for VarMod {
    fn modulo() -> u32 {
        VAR_MOD.load(atomic::Ordering::Relaxed)
    }
}
#[repr(transparent)]
pub struct ModInt<M>(u32, PhantomData<*const M>);
impl<M: Modulo> ModInt<M> {
    pub fn new(x: u32) -> Self {
        debug_assert!(x < M::modulo());
        Self(x, PhantomData)
    }
    pub fn normalize(self) -> Self {
        if self.0 < M::modulo() {
            self
        } else {
            Self::new(self.0 % M::modulo())
        }
    }
    pub fn get(self) -> u32 {
        self.0
    }
    pub fn inv(self) -> Self {
        assert_ne!(self, Self::new(0));
        self.pow(M::modulo() - 2)
    }
    pub fn half(self) -> Self {
        Self::new(self.0 / 2 + self.0 % 2 * ((M::modulo() + 1) / 2))
    }
    pub fn modulo() -> u32 {
        M::modulo()
    }
}
impl<M: Modulo> ops::Neg for ModInt<M> {
    type Output = Self;
    fn neg(self) -> Self {
        Self::new(if self.0 == 0 { 0 } else { M::modulo() - self.0 })
    }
}
impl<M: Modulo> ops::Neg for &'_ ModInt<M> {
    type Output = ModInt<M>;
    fn neg(self) -> Self::Output {
        -(*self)
    }
}
impl<M: Modulo> ops::Add for ModInt<M> {
    type Output = Self;
    fn add(self, rhs: Self) -> Self {
        let s = self.0 + rhs.0;
        Self::new(if s < M::modulo() { s } else { s - M::modulo() })
    }
}
impl<M: Modulo> ops::Sub for ModInt<M> {
    type Output = Self;
    fn sub(self, rhs: Self) -> Self {
        Self::new(if self.0 >= rhs.0 {
            self.0 - rhs.0
        } else {
            M::modulo() + self.0 - rhs.0
        })
    }
}
impl<M: Modulo> ops::Mul for ModInt<M> {
    type Output = Self;
    fn mul(self, rhs: Self) -> Self {
        Self::new((self.0 as u64 * rhs.0 as u64 % M::modulo() as u64) as u32)
    }
}
impl<M: Modulo> ops::Div for ModInt<M> {
    type Output = Self;
    fn div(self, rhs: Self) -> Self {
        self * rhs.inv()
    }
}
macro_rules! op_impl {
    ($($Op:ident $op:ident $OpAssign:ident $op_assign:ident)*) => {
        $(impl<M: Modulo> ops::$Op<&Self> for ModInt<M> {
            type Output = Self;
            fn $op(self, rhs: &Self) -> Self {
                self.$op(*rhs)
            }
        }
        impl<M: Modulo> ops::$Op<ModInt<M>> for &ModInt<M> {
            type Output = ModInt<M>;
            fn $op(self, rhs: ModInt<M>) -> ModInt<M> {
                (*self).$op(rhs)
            }
        }
        impl<M: Modulo> ops::$Op<&ModInt<M>> for &ModInt<M> {
            type Output = ModInt<M>;
            fn $op(self, rhs: &ModInt<M>) -> ModInt<M> {
                (*self).$op(*rhs)
            }
        }
        impl<M: Modulo> ops::$OpAssign for ModInt<M> {
            fn $op_assign(&mut self, rhs: Self) {
                *self = ops::$Op::$op(*self, rhs);
            }
        }
        impl<M: Modulo> ops::$OpAssign<&ModInt<M>> for ModInt<M> {
            fn $op_assign(&mut self, rhs: &ModInt<M>) {
                self.$op_assign(*rhs);
            }
        })*
    };
}
op_impl! {
    Add add AddAssign add_assign
    Sub sub SubAssign sub_assign
    Mul mul MulAssign mul_assign
    Div div DivAssign div_assign
}
impl<M: Modulo> std::iter::Sum for ModInt<M> {
    fn sum<I: Iterator<Item = Self>>(iter: I) -> Self {
        iter.fold(ModInt::new(0), |x, y| x + y)
    }
}
impl<M: Modulo> std::iter::Product for ModInt<M> {
    fn product<I: Iterator<Item = Self>>(iter: I) -> Self {
        iter.fold(ModInt::new(1), |x, y| x * y)
    }
}
pub trait Pow<T> {
    fn pow(self, n: T) -> Self;
}
impl<M: Modulo> Pow<u32> for ModInt<M> {
    fn pow(mut self, mut n: u32) -> Self {
        let mut y = Self::new(1);
        while n > 0 {
            if n % 2 == 1 {
                y *= self;
            }
            self *= self;
            n /= 2;
        }
        y
    }
}
macro_rules! mod_int_pow_impl {
    ($($T:ident)*) => {
        $(impl<M: Modulo> Pow<$T> for ModInt<M> {
            fn pow(self, n: $T) -> Self {
                self.pow(n.rem_euclid(M::modulo() as $T - 1) as u32)
            }
        })*
    };
}
mod_int_pow_impl!(isize i32 i64 usize u64);
macro_rules! mod_int_from_impl {
    ($($T:ident)*) => {
        $(impl<M: Modulo> From<$T> for ModInt<M> {
            #[allow(unused_comparisons)]
            fn from(x: $T) -> Self {
                if M::modulo() <= $T::max_value() as u32 {
                    Self::new(x.rem_euclid(M::modulo() as $T) as u32)
                } else if x < 0 {
                    Self::new((M::modulo() as i32 + x as i32) as u32)
                } else {
                    Self::new(x as u32)
                }
            }
        })*
    }
}
mod_int_from_impl!(isize i8 i16 i32 i64 i128 usize u8 u16 u32 u64 u128);
impl<M: Modulo> From<bool> for ModInt<M> {
    fn from(x: bool) -> Self {
        Self::new(x as u32)
    }
}
impl<M> Copy for ModInt<M> {}
impl<M> Clone for ModInt<M> {
    fn clone(&self) -> Self {
        *self
    }
}
impl<M: Modulo> Default for ModInt<M> {
    fn default() -> Self {
        Self::new(0)
    }
}
impl<M> cmp::PartialEq for ModInt<M> {
    fn eq(&self, other: &Self) -> bool {
        self.0 == other.0
    }
}
impl<M> cmp::Eq for ModInt<M> {}
impl<M> cmp::PartialOrd for ModInt<M> {
    fn partial_cmp(&self, other: &Self) -> Option<cmp::Ordering> {
        self.0.partial_cmp(&other.0)
    }
}
impl<M> cmp::Ord for ModInt<M> {
    fn cmp(&self, other: &Self) -> cmp::Ordering {
        self.0.cmp(&other.0)
    }
}
impl<M> std::hash::Hash for ModInt<M> {
    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
        self.0.hash(state);
    }
}
impl<M> fmt::Display for ModInt<M> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.0.fmt(f)
    }
}
impl<M> fmt::Debug for ModInt<M> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.0.fmt(f)
    }
}


// -----------------------------------------------------------------------------
fn main() -> io::Result<()> {
    std::thread::Builder::new()
        .stack_size(1 << 26)
        .spawn(|| {
            run(
                Scanner::new(io::stdin().lock()),
                io::BufWriter::new(io::stdout().lock()),
            )
        })?
        .join()
        .unwrap();
    Ok(())
}

#[macro_export]
macro_rules! w {
    ($($arg:tt)*) => { write!($($arg)*).unwrap(); }
}
#[macro_export]
macro_rules! wln {
    ($dst:expr $(, $($arg:tt)*)?) => {{
        writeln!($dst $(, $($arg)*)?).unwrap();
        #[cfg(debug_assertions)]
        $dst.flush().unwrap();
    }}
}
#[macro_export]
macro_rules! w_iter {
    ($dst:expr, $fmt:expr, $iter:expr, $delim:expr) => {{
        let mut first = true;
        for elem in $iter {
            if first {
                w!($dst, $fmt, elem);
                first = false;
            } else {
                w!($dst, concat!($delim, $fmt), elem);
            }
        }
    }};
    ($dst:expr, $fmt:expr, $iter:expr) => {
        w_iter!($dst, $fmt, $iter, " ")
    };
}
#[macro_export]
macro_rules! w_iter_ln {
    ($dst:expr, $($t:tt)*) => {{
        w_iter!($dst, $($t)*);
        wln!($dst);
    }}
}
#[macro_export]
macro_rules! e {
    ($($t:tt)*) => {
        #[cfg(debug_assertions)]
        eprint!($($t)*)
    }
}
#[macro_export]
macro_rules! eln {
    ($($t:tt)*) => {
        #[cfg(debug_assertions)]
        eprintln!($($t)*)
    }
}
#[macro_export]
macro_rules! __tstr {
    ($h:expr $(, $t:expr)+) => { concat!(__tstr!($($t),+), ", ", __tstr!(@)) };
    ($h:expr) => { concat!(__tstr!(), " ",  __tstr!(@)) };
    () => { "\x1B[94m[{}:{}]\x1B[0m" };
    (@) => { "\x1B[1;92m{}\x1B[0m = {:?}" }
}
#[macro_export]
macro_rules! d {
    ($($a:expr),*) => { eln!(__tstr!($($a),*), file!(), line!(), $(stringify!($a), $a),*) };
}

pub mod kyoproio {
    use std::{
        fmt::Display,
        io::{self, prelude::*},
        iter::FromIterator,
        marker::PhantomData,
        mem::{self, MaybeUninit},
        str,
    };

    pub trait Input {
        fn bytes(&mut self) -> &[u8];
        fn str(&mut self) -> &str {
            str::from_utf8(self.bytes()).unwrap()
        }
        fn parse<T: Parse>(&mut self) -> T {
            T::parse(self)
        }
        fn parse_iter<T: Parse>(&mut self) -> ParseIter<T, Self> {
            ParseIter(self, PhantomData)
        }
        fn collect<T: Parse, B: FromIterator<T>>(&mut self, n: usize) -> B {
            self.parse_iter().take(n).collect()
        }
        fn map<T: Parse, U, F: FnMut(T) -> U, B: FromIterator<U>>(&mut self, n: usize, f: F) -> B {
            self.parse_iter().take(n).map(f).collect()
        }
    }
    impl<I: Input> Input for &mut I {
        fn bytes(&mut self) -> &[u8] {
            (**self).bytes()
        }
    }
    pub struct Scanner<R> {
        src: R,
        buf: Vec<u8>,
        pos: usize,
        len: usize,
    }
    impl<R: Read> Scanner<R> {
        pub fn new(src: R) -> Self {
            Self {
                src,
                buf: vec![0; 1 << 16],
                pos: 0,
                len: 0,
            }
        }
        fn read(&mut self) -> usize {
            if self.pos > 0 {
                self.buf.copy_within(self.pos..self.len, 0);
                self.len -= self.pos;
                self.pos = 0;
            } else if self.len >= self.buf.len() {
                self.buf.resize(2 * self.buf.len(), 0);
            }
            let n = self.src.read(&mut self.buf[self.len..]).unwrap();
            self.len += n;
            assert!(self.len <= self.buf.len());
            n
        }
    }
    impl<R: Read> Input for Scanner<R> {
        fn bytes(&mut self) -> &[u8] {
            loop {
                while let Some(d) = unsafe { self.buf.get_unchecked(self.pos..self.len) }
                    .iter()
                    .position(u8::is_ascii_whitespace)
                {
                    let p = self.pos;
                    self.pos += d + 1;
                    if d > 0 {
                        return unsafe { self.buf.get_unchecked(p..p + d) };
                    }
                }
                if self.read() == 0 {
                    let p = self.pos;
                    self.pos = self.len;
                    return unsafe { self.buf.get_unchecked(p..self.len) };
                }
            }
        }
    }
    pub struct ParseIter<'a, T, I: ?Sized>(&'a mut I, PhantomData<*const T>);
    impl<'a, T: Parse, I: Input + ?Sized> Iterator for ParseIter<'a, T, I> {
        type Item = T;
        fn next(&mut self) -> Option<T> {
            Some(self.0.parse())
        }
        fn size_hint(&self) -> (usize, Option<usize>) {
            (!0, None)
        }
    }
    pub trait Parse: Sized {
        fn parse<I: Input + ?Sized>(src: &mut I) -> Self;
    }
    macro_rules! from_bytes {
        ($($T:ty)*) => {$(
            impl Parse for $T {
                fn parse<I: Input + ?Sized>(src: &mut I) -> Self {
                    src.bytes().into()
                }
            }
        )*}
    }
    from_bytes!(Vec<u8> Box<[u8]>);
    macro_rules! from_str {
        ($($T:ty)*) => {$(
            impl Parse for $T {
                fn parse<I: Input + ?Sized>(src: &mut I) -> Self {
                    src.str().parse::<$T>().unwrap()
                }
            }
        )*}
    }
    from_str!(String char bool f32 f64);
    macro_rules! int {
        ($($I:ty: $U:ty)*) => {$(
            impl Parse for $I {
                fn parse<I: Input + ?Sized>(src: &mut I) -> Self {
                    let f = |s: &[u8]| s.iter().fold(0, |x, b| 10 * x + (b & 0xf) as $I);
                    let s = src.bytes();
                    if let Some((&b'-', t)) = s.split_first() { -f(t) } else { f(s) }
                }
            }
            impl Parse for $U {
                fn parse<I: Input + ?Sized>(src: &mut I) -> Self {
                    src.bytes().iter().fold(0, |x, b| 10 * x + (b & 0xf) as $U)
                }
            }
        )*}
    }
    int!(isize:usize i8:u8 i16:u16 i32:u32 i64:u64 i128:u128);
    macro_rules! tuple {
        ($H:ident $($T:ident)*) => {
            impl<$H: Parse, $($T: Parse),*> Parse for ($H, $($T),*) {
                fn parse<I: Input + ?Sized>(src: &mut I) -> Self {
                    ($H::parse(src), $($T::parse(src)),*)
                }
            }
            tuple!($($T)*);
        };
        () => {}
    }
    tuple!(A B C D E F G);
    macro_rules! array {
        ($($N:literal)*) => {$(
            impl<T: Parse> Parse for [T; $N] {
                fn parse<I: Input + ?Sized>(src: &mut I) -> Self {
                    unsafe {
                        let mut arr: [MaybeUninit<T>; $N] = MaybeUninit::uninit().assume_init();
                        for elem in &mut arr {
                            *elem = MaybeUninit::new(src.parse());
                        }
                        mem::transmute_copy(&arr)
                    }
                }
            }
        )*}
    }
    array!(1 2 3 4 5 6 7 8);
}