結果

問題 No.1300 Sum of Inversions
ユーザー cotton_fn_cotton_fn_
提出日時 2020-11-27 22:17:38
言語 Rust
(1.83.0 + proconio)
結果
AC  
実行時間 82 ms / 2,000 ms
コード長 11,526 bytes
コンパイル時間 17,064 ms
コンパイル使用メモリ 404,080 KB
実行使用メモリ 10,212 KB
最終ジャッジ日時 2024-07-26 13:16:30
合計ジャッジ時間 20,657 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge2
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 34
権限があれば一括ダウンロードができます

ソースコード

diff # 

#![allow(unused_imports, unused_macros)]

use kyoproio::*;
use std::{
    collections::*,
    io::{self, prelude::*},
    iter,
    mem::{replace, swap},
};

fn run<I: Input, O: Write>(mut kin: I, mut out: O) {
    macro_rules! output { ($($args:expr),+) => { write!(&mut out, $($args),+).unwrap(); }; }
    macro_rules! outputln {
        ($($args:expr),+) => { output!($($args),+); outputln!(); };
        () => { output!("\n"); if cfg!(debug_assertions) { out.flush().unwrap(); } }
    }

    let n: usize = kin.input();
    let a: Vec<_> = kin.iter::<i32>().take(n).map(|x| mint(x)).collect();
    let mut sa = a.clone();
    sa.sort_by_key(|x| -x.get());
    sa.dedup();
    let map: HashMap<_, _> = sa.into_iter().enumerate().map(|(i, x)| (x, i)).collect();
    let make_ft = || FenwickTree::new(n, || mint(0), |x, y| *x + *y);
    let mut ft_sum1 = make_ft();
    let mut ft_cnt1 = make_ft();
    let mut ft_sum2 = make_ft();
    let mut ft_cnt2 = make_ft();
    let mut ans = mint(0);
    for x in a {
        let i = *map.get(&x).unwrap();
        let x = x.normalize();
        ft_sum1.add(i, x);
        ft_cnt1.add(i, mint(1));
        ft_sum2.add(i, ft_sum1.sum(i) + ft_cnt1.sum(i) * x);
        ft_cnt2.add(i, ft_cnt1.sum(i));
        ans += ft_sum2.sum(i) + ft_cnt2.sum(i) * x;
    }
    outputln!("{}", ans.normalize());
}

pub struct FenwickTree<T, F, Z> {
    a: Vec<T>,
    f: F,
    z: Z,
}
impl<T, F: Fn(&T, &T) -> T, Z: Fn() -> T> FenwickTree<T, F, Z> {
    pub fn new(n: usize, z: Z, f: F) -> Self {
        Self {
            a: (0..=n).map(|_| z()).collect(),
            f,
            z,
        }
    }
    pub fn add(&mut self, mut i: usize, x: T) {
        i += 1;
        while i < self.a.len() {
            self.a[i] = (self.f)(&self.a[i], &x);
            i += i & (!i + 1);
        }
    }
    // [0, i)
    pub fn sum(&self, mut i: usize) -> T {
        let mut s = (self.z)();
        while i > 0 {
            s = (self.f)(&self.a[i], &s);
            i -= i & (!i + 1);
        }
        s
    }
    pub fn reset(&mut self) {
        for a in &mut self.a {
            *a = (self.z)();
        }
    }
}


pub type Mint = ModInt<Mod998244353>;
pub fn mint<T: Into<i32>>(x: T) -> ModInt<Mod998244353> {
    ModInt::new(x.into())
}
pub trait Modulo: Copy {
    fn modulo() -> i32;
}
macro_rules! modulo_impl {
    ($($Type:ident $val:tt)*) => {
        $(#[derive(Copy, Clone, Eq, PartialEq, Default, Hash)]
        pub struct $Type;
        impl Modulo for $Type {
            fn modulo() -> i32 {
                $val
            }
        })*
    };
}
modulo_impl!(Mod998244353 998244353 Mod1e9p7 1000000007);
use std::sync::atomic;
#[derive(Copy, Clone, Eq, PartialEq, Default, Hash)]
pub struct VarMod;
static VAR_MOD: atomic::AtomicI32 = atomic::AtomicI32::new(0);
pub fn set_var_mod(m: i32) {
    VAR_MOD.store(m, atomic::Ordering::Relaxed);
}
impl Modulo for VarMod {
    fn modulo() -> i32 {
        VAR_MOD.load(atomic::Ordering::Relaxed)
    }
}
use std::{fmt, marker::PhantomData, ops};
#[derive(Copy, Clone, Eq, PartialEq, Hash)]
pub struct ModInt<M>(i32, PhantomData<M>);
impl<M: Modulo> ModInt<M> {
    pub fn new(x: i32) -> Self {
        debug_assert!(x < M::modulo());
        Self(x, PhantomData)
    }
    pub fn normalize(self) -> Self {
        if self.0 < self.m() && 0 <= self.0 {
            self
        } else {
            Self::new(self.0.rem_euclid(self.m()))
        }
    }
    pub fn get(self) -> i32 {
        self.0
    }
    pub fn inv(self) -> Self {
        self.pow(self.m() - 2)
    }
    pub fn pow(self, mut n: i32) -> Self {
        while n < 0 {
            n += self.m() - 1;
        }
        let mut x = self;
        let mut y = Self::new(1);
        while n > 0 {
            if n % 2 == 1 {
                y *= x;
            }
            x *= x;
            n /= 2;
        }
        y
    }
    pub fn half(self) -> Self {
        Self::new(self.0 / 2 + self.0 % 2 * ((self.m() + 1) / 2))
    }
    pub fn modulo() -> i32 {
        M::modulo()
    }
    fn m(self) -> i32 {
        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 { self.m() - self.0 })
    }
}
impl<M: Modulo> ops::AddAssign for ModInt<M> {
    fn add_assign(&mut self, rhs: Self) {
        self.0 += rhs.0;
        if self.0 >= self.m() {
            self.0 -= self.m();
        }
    }
}
impl<M: Modulo> ops::SubAssign for ModInt<M> {
    fn sub_assign(&mut self, rhs: Self) {
        self.0 -= rhs.0;
        if self.0 < 0 {
            self.0 += self.m();
        }
    }
}
impl<M: Modulo> ops::MulAssign for ModInt<M> {
    fn mul_assign(&mut self, rhs: Self) {
        self.0 = (self.0 as u32 as u64 * rhs.0 as u32 as u64 % self.m() as u32 as u64) as i32;
    }
}
impl<M: Modulo> ops::DivAssign for ModInt<M> {
    fn div_assign(&mut self, rhs: Self) {
        assert_ne!(rhs.0, 0);
        *self *= rhs.inv();
    }
}
macro_rules! op_impl {
    ($($Op:ident $op:ident $OpAssign:ident $op_assign:ident)*) => {
        $(impl<M: Modulo> ops::$Op for ModInt<M> {
            type Output = Self;
            fn $op(self, rhs: Self) -> Self {
                let mut res = self;
                ops::$OpAssign::$op_assign(&mut res, rhs);
                res
            }
        })*
    };
}
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)
    }
}
impl<M: Modulo> fmt::Display for ModInt<M> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.0.fmt(f)
    }
}
impl<M: Modulo> fmt::Debug for ModInt<M> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.pad("ModInt(")?;
        self.0.fmt(f)?;
        f.pad(")")
    }
}


// -----------------------------------------------------------------------------
fn main() -> io::Result<()> {
    std::thread::Builder::new()
        .stack_size(64 * 1024 * 1024)
        .spawn(|| {
            run(
                KInput::new(io::stdin()),
                io::BufWriter::new(io::stdout().lock()),
            )
        })?
        .join()
        .unwrap();
    Ok(())
}

// -----------------------------------------------------------------------------
pub mod kyoproio {
    use std::{io::prelude::*, mem};
    pub trait Input {
        fn bytes(&mut self) -> &[u8];
        fn str(&mut self) -> &str {
            std::str::from_utf8(self.bytes()).unwrap()
        }
        fn input<T: InputParse>(&mut self) -> T {
            T::input(self)
        }
        fn iter<T: InputParse>(&mut self) -> Iter<T, Self> {
            Iter(self, std::marker::PhantomData)
        }
        fn seq<T: InputParse, B: std::iter::FromIterator<T>>(&mut self, n: usize) -> B {
            self.iter().take(n).collect()
        }
    }
    pub struct KInput<R> {
        src: R,
        buf: Vec<u8>,
        pos: usize,
        len: usize,
    }
    impl<R: Read> KInput<R> {
        pub fn new(src: R) -> Self {
            Self {
                src,
                buf: vec![0; 1 << 16],
                pos: 0,
                len: 0,
            }
        }
    }
    impl<R: Read> Input for KInput<R> {
        fn bytes(&mut self) -> &[u8] {
            loop {
                while let Some(delim) = self.buf[self.pos..self.len]
                    .iter()
                    .position(|b| b.is_ascii_whitespace())
                {
                    let p = self.pos;
                    self.pos += delim + 1;
                    if delim > 0 {
                        return &self.buf[p..p + delim];
                    }
                }
                if self.read() == 0 {
                    return &self.buf[mem::replace(&mut self.pos, self.len)..self.len];
                }
            }
        }
    }
    impl<R: Read> KInput<R> {
        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 read = self.src.read(&mut self.buf[self.len..]).unwrap();
            self.len += read;
            read
        }
    }
    pub struct Iter<'a, T, I: ?Sized>(&'a mut I, std::marker::PhantomData<*const T>);
    impl<'a, T: InputParse, I: Input + ?Sized> Iterator for Iter<'a, T, I> {
        type Item = T;
        fn next(&mut self) -> Option<T> {
            Some(self.0.input())
        }
        fn size_hint(&self) -> (usize, Option<usize>) {
            (!0, None)
        }
    }
    pub trait InputParse: Sized {
        fn input<I: Input + ?Sized>(src: &mut I) -> Self;
    }
    impl InputParse for Vec<u8> {
        fn input<I: Input + ?Sized>(src: &mut I) -> Self {
            src.bytes().to_owned()
        }
    }
    macro_rules! from_str_impl {
        { $($T:ty)* } => {
            $(impl InputParse for $T {
                fn input<I: Input + ?Sized>(src: &mut I) -> Self {
                    src.str().parse::<$T>().unwrap()
                }
            })*
        }
    }
    from_str_impl! { String char bool f32 f64 }
    macro_rules! parse_int_impl {
        { $($I:ty: $U:ty)* } => {
            $(impl InputParse for $I {
                fn input<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 InputParse for $U {
                fn input<I: Input + ?Sized>(src: &mut I) -> Self {
                    src.bytes().iter().fold(0, |x, b| 10 * x + (b & 0xf) as $U)
                }
            })*
        };
    }
    parse_int_impl! { isize:usize i8:u8 i16:u16 i32:u32 i64:u64 i128:u128 }
    macro_rules! tuple_impl {
        ($H:ident $($T:ident)*) => {
            impl<$H: InputParse, $($T: InputParse),*> InputParse for ($H, $($T),*) {
                fn input<I: Input + ?Sized>(src: &mut I) -> Self {
                    ($H::input(src), $($T::input(src)),*)
                }
            }
            tuple_impl!($($T)*);
        };
        () => {}
    }
    tuple_impl!(A B C D E F G);
    macro_rules! array_impl {
        { $($N:literal)* } => {
            $(impl<T: InputParse> InputParse for [T; $N] {
                fn input<I: Input + ?Sized>(src: &mut I) -> Self {
                    let mut arr = mem::MaybeUninit::uninit();
                    unsafe {
                        let ptr = arr.as_mut_ptr() as *mut T;
                        for i in 0..$N {
                            ptr.add(i).write(src.input());
                        }
                        arr.assume_init()
                    }
                }
            })*
        };
    }
    array_impl! { 1 2 3 4 5 6 7 8 }
    #[macro_export]
    macro_rules! kdbg {
        ($($v:expr),*) => {
            if cfg!(debug_assertions) { dbg!($($v),*) } else { ($($v),*) }
        }
    }
}
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