#706856 (Rust) No.1144 Triangles

• 問題: No.1144 Triangles
• ユーザー: koba-e964
• 提出日時: 2021-10-12 00:33:06
• 言語: Rust (1.83.0 + proconio)
• 結果: AC
• 実行時間: 628 ms / 3,000 ms
• コード長: 5,665 bytes
• コンパイル時間: 12,745 ms
• コンパイル使用メモリ: 404,876 KB
• 実行使用メモリ: 5,376 KB
• 最終ジャッジ日時: 2024-09-16 06:33:41
• 合計ジャッジ時間: 21,771 ms
• ジャッジサーバーID （参考情報）: judge6 / judge3

ファイルパターン	結果
sample	AC * 4
other	AC * 25

ソースコード

// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    ($($r:tt)*) => {
        let stdin = std::io::stdin();
        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
        let mut next = move || -> String{
            bytes.by_ref().map(|r|r.unwrap() as char)
                .skip_while(|c|c.is_whitespace())
                .take_while(|c|!c.is_whitespace())
                .collect()
        };
        input_inner!{next, $($r)*}
    };
}

macro_rules! input_inner {
    ($next:expr) => {};
    ($next:expr,) => {};
    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };
}

macro_rules! read_value {
    ($next:expr, ( $($t:tt),* )) => { ($(read_value!($next, $t)),*) };
    ($next:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    };
    ($next:expr, $t:ty) => ($next().parse::<$t>().expect("Parse error"));
}

/// Verified by https://atcoder.jp/contests/abc198/submissions/21774342
mod mod_int {
    use std::ops::*;
    pub trait Mod: Copy { fn m() -> i64; }
    #[derive(Copy, Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]
    pub struct ModInt<M> { pub x: i64, phantom: ::std::marker::PhantomData<M> }
    impl<M: Mod> ModInt<M> {
        // x >= 0
        pub fn new(x: i64) -> Self { ModInt::new_internal(x % M::m()) }
        fn new_internal(x: i64) -> Self {
            ModInt { x: x, phantom: ::std::marker::PhantomData }
        }
        pub fn pow(self, mut e: i64) -> Self {
            debug_assert!(e >= 0);
            let mut sum = ModInt::new_internal(1);
            let mut cur = self;
            while e > 0 {
                if e % 2 != 0 { sum *= cur; }
                cur *= cur;
                e /= 2;
            }
            sum
        }
        #[allow(dead_code)]
        pub fn inv(self) -> Self { self.pow(M::m() - 2) }
    }
    impl<M: Mod, T: Into<ModInt<M>>> Add<T> for ModInt<M> {
        type Output = Self;
        fn add(self, other: T) -> Self {
            let other = other.into();
            let mut sum = self.x + other.x;
            if sum >= M::m() { sum -= M::m(); }
            ModInt::new_internal(sum)
        }
    }
    impl<M: Mod, T: Into<ModInt<M>>> Sub<T> for ModInt<M> {
        type Output = Self;
        fn sub(self, other: T) -> Self {
            let other = other.into();
            let mut sum = self.x - other.x;
            if sum < 0 { sum += M::m(); }
            ModInt::new_internal(sum)
        }
    }
    impl<M: Mod, T: Into<ModInt<M>>> Mul<T> for ModInt<M> {
        type Output = Self;
        fn mul(self, other: T) -> Self { ModInt::new(self.x * other.into().x % M::m()) }
    }
    impl<M: Mod, T: Into<ModInt<M>>> AddAssign<T> for ModInt<M> {
        fn add_assign(&mut self, other: T) { *self = *self + other; }
    }
    impl<M: Mod, T: Into<ModInt<M>>> SubAssign<T> for ModInt<M> {
        fn sub_assign(&mut self, other: T) { *self = *self - other; }
    }
    impl<M: Mod, T: Into<ModInt<M>>> MulAssign<T> for ModInt<M> {
        fn mul_assign(&mut self, other: T) { *self = *self * other; }
    }
    impl<M: Mod> Neg for ModInt<M> {
        type Output = Self;
        fn neg(self) -> Self { ModInt::new(0) - self }
    }
    impl<M> ::std::fmt::Display for ModInt<M> {
        fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
            self.x.fmt(f)
        }
    }
    impl<M: Mod> From<i64> for ModInt<M> {
        fn from(x: i64) -> Self { Self::new(x) }
    }
} // mod mod_int

macro_rules! define_mod {
    ($struct_name: ident, $modulo: expr) => {
        #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
        struct $struct_name {}
        impl mod_int::Mod for $struct_name { fn m() -> i64 { $modulo } }
    }
}
const MOD: i64 = 1_000_000_007;
define_mod!(PP, MOD);
type MInt = mod_int::ModInt<PP>;

type Coord = i64; // the type of coordinates

fn arg_sort(xy: &mut [(Coord, Coord, i32)]) {
    fn half((x, y, _): (Coord, Coord, i32)) -> i32 {
        assert_ne!((x, y), (0, 0));
        if y >= 0 {
            if x > 0 || y > 0 {
                1
            } else {
                2
            }
        } else {
            2
        }
    }
    xy.sort_unstable_by(|&a, &b| {
        half(a).cmp(&half(b)).then_with(
            || 0.cmp(&(a.0 * b.1 - a.1 * b.0))
                .then_with(|| a.2.cmp(&b.2)))
    });
}

fn calc(a: Vec<(i64, i64)>) -> MInt {
    let n = a.len();
    let mut b = vec![];
    for (x, y) in a {
        b.push((x, y, 0));
        b.push((-x, -y, 1));
    }
    arg_sort(&mut b);
    let mut acc_x = vec![MInt::new(0); 3 * n + 1];
    let mut acc_y = vec![MInt::new(0); 3 * n + 1];
    let mut tot = MInt::new(0);
    for i in 0..3 * n {
        let (x, y) = if b[i % (2 * n)].2 == 0 {
            (MOD + b[i % (2 * n)].0, MOD + b[i % (2 * n)].1)
        } else {
            (0, 0)
        };
        acc_x[i + 1] = acc_x[i] + x;
        acc_y[i + 1] = acc_y[i] + y;
    }
    for i in 0..2 * n {
        if b[i].2 != 0 { continue; }
        let p = acc_x[i + n] - acc_x[i];
        let q = acc_y[i + n] - acc_y[i];
        tot += q * (MOD + b[i].0) - p * (MOD + b[i].1);
    }
    tot
}

// Tags: counting, area-of-triangles, sort-by-argument
fn main() {
    input! {
        n: usize,
        xy: [(i64, i64); n],
    }
    let mut tot = MInt::new(0);
    for i in 0..n {
        let (x, y) = xy[i];
        let v: Vec<_> = xy[i + 1..].iter().map(|&(a, b)| (a - x, b - y))
            .filter(|&p| p != (0, 0)).collect();
        tot += calc(v);
    }
    println!("{}", tot);
}