#468445 (Rust) No.743 Segments on a Polygon

• 問題: No.743 Segments on a Polygon
• ユーザー: cotton_fn_
• 提出日時: 2020-04-23 13:36:50
• 言語: Rust (1.77.0)
• 結果: AC
• 実行時間: 20 ms / 2,000 ms
• コード長: 5,110 bytes
• コンパイル時間: 1,132 ms
• コンパイル使用メモリ: 173,184 KB
• 実行使用メモリ: 5,376 KB
• 最終ジャッジ日時: 2024-04-21 13:40:03
• 合計ジャッジ時間: 2,663 ms
• ジャッジサーバーID （参考情報）: judge2 / judge5

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	20 ms; 5,248 KB
testcase_01	AC	20 ms; 5,376 KB
testcase_02	AC	18 ms; 5,376 KB
testcase_03	AC	19 ms; 5,376 KB
testcase_04	AC	19 ms; 5,376 KB
testcase_05	AC	20 ms; 5,376 KB
testcase_06	AC	19 ms; 5,376 KB
testcase_07	AC	19 ms; 5,376 KB
testcase_08	AC	19 ms; 5,376 KB
testcase_09	AC	16 ms; 5,376 KB

ソースコード

#![allow(unused)]

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

fn main() -> io::Result<()> {
    std::thread::Builder::new()
        .stack_size(64 * 1024 * 1024)
        .spawn(solve)?
        .join()
        .unwrap();
    Ok(())
}

fn solve() {
    let stdin = io::stdin();
    let mut kin = KInput::new(stdin.lock());
    let stdout = io::stdout();
    let mut out = io::BufWriter::new(stdout.lock());
    macro_rules! output { ($($args:tt),+) => { write!(&mut out, $($args),+) }; }
    macro_rules! outputln {
        ($($args:tt),+) => { output!($($args),+); outputln!(); };
        () => { output!("\n"); if cfg!(debug_assertions) { out.flush(); } }
    }

    let (n, m): (usize, usize) = kin.input();
    let mut s = vec![!0; m];
    for _ in 0..n {
        let (a, b): (usize, usize) = kin.input();
        s[a] = b;
        s[b] = a;
    }

    let mut ans = 0i64;
    let mut f = || {
        let mut fen = FenwickTree::new(m, || 0, |&x, &y| x + y);
        for i in 0..m {
            if s[i] != !0 {
                if i < s[i] {
                    fen.apply(i, 1);
                } else {
                    fen.apply(s[i], -1);
                    ans += fen.fold(m) - fen.fold(s[i]);
                }
            }
        }
    };
    f();
    outputln!("{}", ans);
}

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: std::iter::repeat_with(&z).take(n + 1).collect(),
            f,
            z,
        }
    }
    pub fn apply(&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 fold(&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 mod kyoproio {
    #![warn(unused)]
    use std::io::prelude::*;
    pub trait Input {
        fn str(&mut self) -> &str;
        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: String,
        pos: usize,
    }
    impl<R: BufRead> KInput<R> {
        pub fn new(src: R) -> Self {
            Self {
                src,
                buf: String::with_capacity(1024),
                pos: 0,
            }
        }
    }
    impl<R: BufRead> Input for KInput<R> {
        fn str(&mut self) -> &str {
            loop {
                if self.pos >= self.buf.len() {
                    self.pos = 0;
                    self.buf.clear();
                    if self.src.read_line(&mut self.buf).expect("io error") == 0 {
                        return &self.buf;
                    }
                }
                let range = self.pos
                    ..self.buf[self.pos..]
                        .find(|c: char| c.is_ascii_whitespace())
                        .map(|i| i + self.pos)
                        .unwrap_or_else(|| self.buf.len());
                self.pos = range.end + 1;
                if range.end > range.start {
                    return &self.buf[range];
                }
            }
        }
    }
    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())
        }
    }
    pub trait InputParse: Sized {
        fn input<I: Input + ?Sized>(input: &mut I) -> Self;
    }
    impl InputParse for Vec<u8> {
        fn input<I: Input + ?Sized>(input: &mut I) -> Self {
            input.str().as_bytes().to_owned()
        }
    }
    macro_rules! from_str_impl {
        { $($T:ty)* } => {
            $(impl InputParse for $T {
                fn input<I: Input + ?Sized>(input: &mut I) -> Self {
                    input.str().parse::<$T>().expect("parse error")
                }
            })*
        }
    }
    from_str_impl! {
        String char bool f32 f64 isize i8 i16 i32 i64 i128 usize u8 u16 u32 u64 u128
    }
    macro_rules! tuple_impl {
        ($H:ident $($T:ident)*) => {
            impl<$H: InputParse, $($T: InputParse),*> InputParse for ($H, $($T),*) {
                fn input<I: Input + ?Sized>(input: &mut I) -> Self {
                    ($H::input(input), $($T::input(input)),*)
                }
            }
            tuple_impl!($($T)*);
        };
        () => {}
    }
    tuple_impl!(A B C D E F G);
}