#638256 (Rust) No.90 品物の並び替え

• 問題: No.90 品物の並び替え
• ユーザー: sino
• 提出日時: 2021-04-01 15:02:52
• 言語: Rust (1.77.0 + proconio)
• 結果: AC
• 実行時間: 348 ms / 5,000 ms
• コード長: 4,036 bytes
• コンパイル時間: 12,906 ms
• コンパイル使用メモリ: 404,992 KB
• 実行使用メモリ: 6,820 KB
• 最終ジャッジ日時: 2024-12-17 19:05:20
• 合計ジャッジ時間: 13,489 ms
• ジャッジサーバーID （参考情報）: judge2 / judge3

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	1 ms; 6,816 KB
testcase_01	AC	26 ms; 6,816 KB
testcase_02	AC	1 ms; 6,816 KB
testcase_03	AC	3 ms; 6,816 KB
testcase_04	AC	3 ms; 6,820 KB
testcase_05	AC	28 ms; 6,816 KB
testcase_06	AC	21 ms; 6,816 KB
testcase_07	AC	1 ms; 6,816 KB
testcase_08	AC	1 ms; 6,820 KB
testcase_09	AC	348 ms; 6,820 KB

ソースコード

#[allow(unused_macros)]
macro_rules! read {
    ([$t:ty] ; $n:expr) =>
        ((0..$n).map(|_| read!([$t])).collect::<Vec<_>>());
    ($($t:ty),+ ; $n:expr) =>
        ((0..$n).map(|_| read!($($t),+)).collect::<Vec<_>>());
    ([$t:ty]) =>
        (rl().split_whitespace().map(|w| w.parse().unwrap()).collect::<Vec<$t>>());
    ($t:ty) =>
        (rl().parse::<$t>().unwrap());
    ($($t:ty),*) => {{
        let buf = rl();
        let mut w = buf.split_whitespace();
        ($(w.next().unwrap().parse::<$t>().unwrap()),*)
    }};
}

#[allow(dead_code)]
fn rl() -> String {
    let mut buf = String::new();
    std::io::stdin().read_line(&mut buf).unwrap();
    buf.trim_end().to_owned()
}

fn main() {
    let (n, m) = read!(usize, usize);
    let table = read!([usize]; m);

    let mut max_score = 0;
    // let mut best_order: Vec<usize> = (0..n).collect();

    let mut order: Vec<usize> = (0..n).collect();
    loop {
        let mut score = 0;
        // calc point.
        for data in &table {
            let (item1, item2, s) = (data[0], data[1], data[2]);

            // find index of item1
            let mut i1 = 0;
            for i in 0..n {
                if order[i] == item1 {
                    i1 = i;
                    break;
                }
            }

            for i in i1+1..n {
                if order[i] == item2 {
                    score += s;
                    break;
                }
            }
        }

        // update best order
        if score >= max_score {
            // best_order = order.clone();
            max_score = score;
        }

        // update order
        if !order.next_permutation() {
            break;
        }
    }

    // println!("{:?}", best_order);
    println!("{}", max_score);
}

pub trait LexicalPermutation {
    /// Return `true` if the slice was permuted, `false` if it is already
    /// at the last ordered permutation.
    fn next_permutation(&mut self) -> bool;
    /// Return `true` if the slice was permuted, `false` if it is already
    /// at the first ordered permutation.
    fn prev_permutation(&mut self) -> bool;
}

impl<T> LexicalPermutation for [T] where T: Ord {
    /// Original author in Rust: Thomas Backman <[e-mail]>
    fn next_permutation(&mut self) -> bool {
        // These cases only have 1 permutation each, so we can't do anything.
        if self.len() < 2 { return false; }

        // Step 1: Identify the longest, rightmost weakly decreasing part of the vector
        let mut i = self.len() - 1;
        while i > 0 && self[i-1] >= self[i] {
            i -= 1;
        }

        // If that is the entire vector, this is the last-ordered permutation.
        if i == 0 {
            return false;
        }

        // Step 2: Find the rightmost element larger than the pivot (i-1)
        let mut j = self.len() - 1;
        while j >= i && self[j] <= self[i-1]  {
            j -= 1;
        }

        // Step 3: Swap that element with the pivot
        self.swap(j, i-1);

        // Step 4: Reverse the (previously) weakly decreasing part
        self[i..].reverse();

        true
    }

    fn prev_permutation(&mut self) -> bool {
        // These cases only have 1 permutation each, so we can't do anything.
        if self.len() < 2 { return false; }

        // Step 1: Identify the longest, rightmost weakly increasing part of the vector
        let mut i = self.len() - 1;
        while i > 0 && self[i-1] <= self[i] {
            i -= 1;
        }

        // If that is the entire vector, this is the first-ordered permutation.
        if i == 0 {
            return false;
        }

        // Step 2: Reverse the weakly increasing part
        self[i..].reverse();

        // Step 3: Find the rightmost element equal to or bigger than the pivot (i-1)
        let mut j = self.len() - 1;
        while j >= i && self[j-1] < self[i-1]  {
            j -= 1;
        }

        // Step 4: Swap that element with the pivot
        self.swap(i-1, j);

        true
    }

}