#576160 (Rust) No.1279 Array Battle

• 問題: No.1279 Array Battle
• ユーザー: cympfh
• 提出日時: 2020-11-06 21:23:38
• 言語: Rust (1.83.0 + proconio)
• 結果: AC
• 実行時間: 179 ms / 2,000 ms
• コード長: 3,741 bytes
• コンパイル時間: 15,727 ms
• コンパイル使用メモリ: 378,804 KB
• 実行使用メモリ: 5,376 KB
• 最終ジャッジ日時: 2024-07-22 12:01:33
• 合計ジャッジ時間: 15,297 ms
• ジャッジサーバーID （参考情報）: judge1 / judge5

ファイルパターン	結果
other	AC * 20

ソースコード

#![allow(unused_imports, unused_macros, dead_code)]

macro_rules! min {
    (.. $x:expr) => {{
        let mut it = $x.iter();
        it.next().map(|z| it.fold(z, |x, y| min!(x, y)))
    }};
    ($x:expr) => ($x);
    ($x:expr, $($ys:expr),*) => {{
        let t = min!($($ys),*);
        if $x < t { $x } else { t }
    }}
}
macro_rules! max {
    (.. $x:expr) => {{
        let mut it = $x.iter();
        it.next().map(|z| it.fold(z, |x, y| max!(x, y)))
    }};
    ($x:expr) => ($x);
    ($x:expr, $($ys:expr),*) => {{
        let t = max!($($ys),*);
        if $x > t { $x } else { t }
    }}
}
macro_rules! trace {
    ($x:expr) => {
        #[cfg(debug_assertions)]
        eprintln!(">>> {} = {:?}", stringify!($x), $x)
    };
    ($($xs:expr),*) => { trace!(($($xs),*)) }
}
macro_rules! flush {
    () => {
        std::io::stdout().flush().unwrap();
    };
}
macro_rules! put {
    (.. $x:expr) => {{
        let mut it = $x.iter();
        if let Some(x) = it.next() { print!("{}", x); }
        for x in it { print!(" {}", x); }
        println!("");
    }};
    ($x:expr) => { println!("{}", $x) };
    ($x:expr, $($xs:expr),*) => { print!("{} ", $x); put!($($xs),*) }
}

const M: i64 = 1_000_000_007;

// @num/iter/perm
pub struct Permutation {
    n: usize,
    idx: usize,
}
impl Permutation {
    pub fn new(n: usize) -> Permutation {
        Permutation { n: n, idx: 0 }
    }
}
impl Iterator for Permutation {
    type Item = Vec<usize>;
    fn next(&mut self) -> Option<Vec<usize>> {
        let mut r = vec![0; self.n];
        let mut idx = self.idx;
        for k in 1..self.n {
            r[k] = idx % (k + 1);
            idx /= k + 1;
        }
        if idx > 0 {
            return None;
        }
        r.reverse();
        let mut b = vec![true; self.n];
        b[r[0]] = false;
        for k in 1..self.n {
            let mut count = 0;
            for j in 0..self.n {
                if b[j] {
                    if count == r[k] {
                        r[k] = j;
                        b[j] = false;
                        break;
                    }
                    count += 1;
                }
            }
        }
        self.idx += 1;
        return Some(r);
    }
}

fn main() {
    let mut sc = Scanner::new();
    let n: usize = sc.cin();
    let a: Vec<u64> = sc.vec(n);
    let b: Vec<u64> = sc.vec(n);
    let mut mx = 0;
    for p in Permutation::new(n) {
        let mut x = 0;
        for i in 0..n {
            if a[p[i]] > b[i] {
                x += a[p[i]] - b[i];
            }
        }
        mx = max!(mx, x);
    }
    let mut ans = 0;
    for p in Permutation::new(n) {
        let mut x = 0;
        for i in 0..n {
            if a[p[i]] > b[i] {
                x += a[p[i]] - b[i];
            }
        }
        if mx == x {
            ans += 1;
        }
    }
    put!(ans);
}

use std::collections::VecDeque;
use std::io::{self, Write};
use std::str::FromStr;

struct Scanner {
    stdin: io::Stdin,
    buffer: VecDeque<String>,
}
impl Scanner {
    fn new() -> Self {
        Scanner {
            stdin: io::stdin(),
            buffer: VecDeque::new(),
        }
    }
    fn cin<T: FromStr>(&mut self) -> T {
        while self.buffer.is_empty() {
            let mut line = String::new();
            let _ = self.stdin.read_line(&mut line);
            for w in line.split_whitespace() {
                self.buffer.push_back(String::from(w));
            }
        }
        self.buffer.pop_front().unwrap().parse::<T>().ok().unwrap()
    }
    fn chars(&mut self) -> Vec<char> {
        self.cin::<String>().chars().collect()
    }
    fn vec<T: FromStr>(&mut self, n: usize) -> Vec<T> {
        (0..n).map(|_| self.cin()).collect()
    }
}