結果

問題 No.1115 二つの数列 / Two Sequences
ユーザー nebocconebocco
提出日時 2021-03-20 12:36:08
言語 Rust
(1.77.0 + proconio)
結果
AC  
実行時間 12 ms / 2,000 ms
コード長 10,846 bytes
コンパイル時間 14,184 ms
コンパイル使用メモリ 390,700 KB
実行使用メモリ 6,272 KB
最終ジャッジ日時 2024-11-20 21:39:24
合計ジャッジ時間 16,613 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge2
このコードへのチャレンジ
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 2 ms
5,248 KB
testcase_01 AC 1 ms
5,248 KB
testcase_02 AC 1 ms
5,248 KB
testcase_03 AC 11 ms
5,632 KB
testcase_04 AC 12 ms
6,272 KB
testcase_05 AC 11 ms
5,632 KB
testcase_06 AC 9 ms
5,248 KB
testcase_07 AC 12 ms
6,144 KB
testcase_08 AC 1 ms
5,248 KB
testcase_09 AC 7 ms
5,248 KB
testcase_10 AC 10 ms
6,272 KB
testcase_11 AC 1 ms
5,248 KB
testcase_12 AC 12 ms
6,144 KB
testcase_13 AC 12 ms
6,144 KB
testcase_14 AC 11 ms
6,144 KB
testcase_15 AC 2 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
testcase_22 AC 1 ms
5,248 KB
testcase_23 AC 2 ms
5,248 KB
testcase_24 AC 5 ms
5,248 KB
testcase_25 AC 9 ms
5,248 KB
testcase_26 AC 3 ms
5,248 KB
testcase_27 AC 6 ms
5,248 KB
testcase_28 AC 8 ms
5,248 KB
testcase_29 AC 10 ms
5,248 KB
testcase_30 AC 12 ms
6,144 KB
testcase_31 AC 4 ms
5,248 KB
testcase_32 AC 3 ms
5,248 KB
testcase_33 AC 10 ms
5,760 KB
testcase_34 AC 1 ms
5,248 KB
testcase_35 AC 1 ms
5,248 KB
testcase_36 AC 1 ms
5,248 KB
testcase_37 AC 1 ms
5,248 KB
testcase_38 AC 1 ms
5,248 KB
testcase_39 AC 1 ms
5,248 KB
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ソースコード

diff # 

fn main() {
	let mut io = IO::new();
    input!{ from io,
		n: usize,
		a: [Usize1; n],
		b: [Usize1; n]
    }
	let mut re = vec![0; n];
	for i in 0..n {
		re[b[i]] = i;
	}
	let f = a.into_iter().map(|i| re[i]).collect::<Vec<_>>();
	let mut ans = 0;
	let mut bit = FenwickTree::<i64>::new(n);
	for &x in f.iter().rev() {
		ans += bit.sum(..x);
		bit.add(x, 1);
	}
    io.println(ans);
}

// ------------ FenwickTree with generics start ------------

#[derive(Clone, Debug)]
pub struct FenwickTree<T>(Vec<T>);

impl<T: Monoid> FenwickTree<T> {
    #[inline]
    fn lsb(x: usize) -> usize {
        x & x.wrapping_neg()
    }

    pub fn new(n: usize) -> Self {
        Self(vec![T::zero(); n+1])
    }

    pub fn prefix_sum(&self, i: usize) -> T {
        std::iter::successors(Some(i), |&i| Some(i - Self::lsb(i)))
        .take_while(|&i| i != 0)
        .map(|i| self.0[i].clone())
        .fold(T::zero(), |sum, x| sum + x)
    }

    pub fn add(&mut self, i: usize, x: T) {
        let n = self.0.len();
        std::iter::successors(Some(i + 1), |&i| Some(i + Self::lsb(i)))
        .take_while(|&i| i < n)
        .for_each(|i| self.0[i] = self.0[i].clone() + x.clone());
    }

    /// pred(j, sum(..j)) && !pred(j+1, sum(..j+1))
    pub fn partition(&self, pred: impl Fn(usize, &T) -> bool) -> (usize, T) {
        assert!(pred(0, &self.0[0]), "need to be pred(0, 0)");
        let mut j = 0;
        let mut current = self.0[0].clone();
        let n = self.0.len();
        for d in std::iter::successors(Some(n.next_power_of_two() >> 1), |&d| { Some(d >> 1)})
            .take_while(|&d| d != 0)
        {
            if j + d < n {
                let next = current.clone() + self.0[j + d].clone();
                if pred(j + d, &next) {
                    current = next;
                    j += d;
                }
            }
        }
        (j, current)
    }
}

impl<T: Monoid> From<Vec<T>> for FenwickTree<T> {
    fn from(src: Vec<T>) -> Self {
        let mut table = std::iter::once(T::zero())
            .chain(src.into_iter())
            .collect::<Vec<T>>();
        let n = table.len();
        (1..n)
            .map(|i| (i, i + Self::lsb(i)))
            .filter(|&(_, j)| j < n)
            .for_each(|(i, j)| {
                table[j] = table[j].clone() + table[i].clone();
            });
        Self(table)
    }
}

impl<T: Group> FenwickTree<T> {
    pub fn sum<R: RangeBounds<usize>>(&self, rng: R) -> T {
        let Range { start, end } = bounds_within(rng, self.0.len() - 1);
        self.prefix_sum(end) + -self.prefix_sum(start)
    }
}

// ------------ FenwickTree with generics end ------------


// ------------ algebraic traits start ------------
use std::marker::Sized;
use std::ops::*;

/// 元
pub trait Element: Sized + Clone + PartialEq {}
impl<T: Sized + Clone + PartialEq> Element for T {}

/// 結合性
pub trait Associative: Magma {}

/// マグマ
pub trait Magma: Element + Add<Output=Self> {}
impl<T: Element + Add<Output=Self>> Magma for T {}

/// 半群
pub trait SemiGroup: Magma + Associative {}
impl<T: Magma + Associative> SemiGroup for T {}

/// モノイド
pub trait Monoid: SemiGroup + Zero {}
impl<T: SemiGroup + Zero> Monoid for T {}

pub trait ComMonoid: Monoid + AddAssign {}
impl<T: Monoid + AddAssign> ComMonoid for T {}

/// 群
pub trait Group: Monoid + Neg<Output=Self> {}
impl<T: Monoid + Neg<Output=Self>> Group for T {}

pub trait ComGroup: Group + ComMonoid {}
impl<T: Group + ComMonoid> ComGroup for T {}

/// 半環
pub trait SemiRing: ComMonoid + Mul<Output=Self> + One {}
impl<T: ComMonoid + Mul<Output=Self> + One> SemiRing for T {}

/// 環
pub trait Ring: ComGroup + SemiRing {}
impl<T: ComGroup + SemiRing> Ring for T {}

pub trait ComRing: Ring + MulAssign {}
impl<T: Ring + MulAssign> ComRing for T {}

/// 体
pub trait Field: ComRing + Div<Output=Self> + DivAssign {}
impl<T: ComRing + Div<Output=Self> + DivAssign> Field for T {}

/// 加法単元
pub trait Zero: Element {
    fn zero() -> Self;
    fn is_zero(&self) -> bool {
        *self == Self::zero()
    }
}

/// 乗法単元
pub trait One: Element {
    fn one() -> Self;
    fn is_one(&self) -> bool {
        *self == Self::one()
    }
}

macro_rules! impl_integer {
    ($($T:ty,)*) => {
        $(
            impl Associative for $T {}

            impl Zero for $T {
                fn zero() -> Self { 0 }
                fn is_zero(&self) -> bool { *self == 0 }
            }

            impl<'a> Zero for &'a $T {
                fn zero() -> Self { &0 }
                fn is_zero(&self) -> bool { *self == &0 }
            }

            impl One for $T {
                fn one() -> Self { 1 }
                fn is_one(&self) -> bool { *self == 1 }
            }

            impl<'a> One for &'a $T {
                fn one() -> Self { &1 }
                fn is_one(&self) -> bool { *self == &1 }
            }
        )*
    };
}

impl_integer! {
    i8, i16, i32, i64, i128, isize,
    u8, u16, u32, u64, u128, usize,
}
// ------------ algebraic traits end ------------


use std::ops::Bound::{Excluded, Included, Unbounded};
use std::ops::{Range, RangeBounds};

/// 区間を配列サイズに収まるように丸める。
///
/// 与えられた区間 `r` と `0..len` の共通部分を、有界な半開区間として返す。
///
/// # Examples
/// ```
/// use bibliotheca::utils::bounds::bounds_within;
///
/// assert_eq!(bounds_within(.., 7), 0..7);
/// assert_eq!(bounds_within(..=4, 7), 0..5);
/// ```
pub fn bounds_within<R: RangeBounds<usize>>(r: R, len: usize) -> Range<usize> {
    let e_ex = match r.end_bound() {
        Included(&e) => e + 1,
        Excluded(&e) => e,
        Unbounded => len,
    }
    .min(len);
    let s_in = match r.start_bound() {
        Included(&s) => s,
        Excluded(&s) => s + 1,
        Unbounded => 0,
    }
    .min(e_ex);
    s_in..e_ex
}


// ------------ 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, f32, f64);

impl Scan for char {
	type Output = char;
	fn scan(s: &mut IO) -> Self::Output {
		s.scan_str().chars().next().unwrap()
	}
}

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, f32, f64);

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; $len1:expr]; $len2:expr] $($rest:tt)*) => {
			let $($mut)* $var = (0..$len2).map(|_| $io.scan_vec::<$kind>($len1)).collect::<Vec<Vec<$kind>>>();
			input!(@start $io @read @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 ------------
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