#471928 (Rust) No.245 貫け！

• 問題: No.245 貫け！
• ユーザー: cotton_fn_
• 提出日時: 2020-04-28 03:07:59
• 言語: Rust (1.77.0 + proconio)
• 結果: AC
• 実行時間: 10 ms / 5,000 ms
• コード長: 4,560 bytes
• コンパイル時間: 11,100 ms
• コンパイル使用メモリ: 385,520 KB
• 実行使用メモリ: 5,376 KB
• 最終ジャッジ日時: 2024-05-02 08:59:09
• 合計ジャッジ時間: 12,345 ms
• ジャッジサーバーID （参考情報）: judge5 / 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	2 ms; 5,376 KB
testcase_02	AC	1 ms; 5,376 KB
testcase_03	AC	2 ms; 5,376 KB
testcase_04	AC	1 ms; 5,376 KB
testcase_05	AC	1 ms; 5,376 KB
testcase_06	AC	1 ms; 5,376 KB
testcase_07	AC	1 ms; 5,376 KB
testcase_08	AC	1 ms; 5,376 KB
testcase_09	AC	2 ms; 5,376 KB
testcase_10	AC	2 ms; 5,376 KB
testcase_11	AC	4 ms; 5,376 KB
testcase_12	AC	10 ms; 5,376 KB
testcase_13	AC	10 ms; 5,376 KB
testcase_14	AC	10 ms; 5,376 KB
testcase_15	AC	10 ms; 5,376 KB
testcase_16	AC	10 ms; 5,376 KB
testcase_17	AC	10 ms; 5,376 KB
testcase_18	AC	10 ms; 5,376 KB
testcase_19	AC	8 ms; 5,376 KB

ソースコード

#![allow(unused_imports, unused_macros)]

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: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 ls: Vec<((i32, i32), (i32, i32))> = kin.seq(n);
    let mut ans = 0;
    for &p1 in ls.iter().flat_map(|(a, b)| vec![a, b]) {
        for &p2 in ls.iter().flat_map(|(a, b)| vec![a, b]) {
            if p1 == p2 {
                continue;
            }
            let p = sub(p1, p2);
            let mut cnt = 0;
            for &(f, t) in ls.iter() {
                if cross(p, sub(f, p2)) * cross(p, sub(t, p2)) <= 0 {
                    cnt += 1;
                }
            }
            ans = ans.max(cnt);
        }
    }
    outputln!("{}", ans);
}

fn sub((x1, y1): (i32, i32), (x2, y2): (i32, i32)) -> (i32, i32) {
    (x1 - x2, y1 - y2)
}
fn cross((x1, y1): (i32, i32), (x2, y2): (i32, i32)) -> i32 {
    x1 * y2 - x2 * y1    
}


// -----------------------------------------------------------------------------
pub mod kyoproio {
    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>(src: &mut I) -> Self;
    }
    impl InputParse for Vec<u8> {
        fn input<I: Input + ?Sized>(src: &mut I) -> Self {
            src.str().as_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>().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>(src: &mut I) -> Self {
                    ($H::input(src), $($T::input(src)),*)
                }
            }
            tuple_impl!($($T)*);
        };
        () => {}
    }
    tuple_impl!(A B C D E F G);
}