結果

問題 No.1300 Sum of Inversions
ユーザー phspls
提出日時 2022-12-15 23:26:27
言語 Rust
(1.83.0 + proconio)
結果
AC  
実行時間 354 ms / 2,000 ms
コード長 3,125 bytes
コンパイル時間 14,614 ms
コンパイル使用メモリ 385,932 KB
実行使用メモリ 28,256 KB
最終ジャッジ日時 2024-11-14 15:07:00
合計ジャッジ時間 25,755 ms
ジャッジサーバーID
（参考情報） 		judge3 / judge5
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 34
権限があれば一括ダウンロードができます
コンパイルメッセージ
warning: field `orgn` is never read
 --> src/main.rs:7:5
  |
5 | struct SegmentTree<F, T> {
  |        ----------- field in this struct
6 |     n: usize,
7 |     orgn: usize,
  |     ^^^^
  |
  = note: `SegmentTree` has derived impls for the traits `Clone` and `Debug`, but these are intentionally ignored during dead code analysis
  = note: `#[warn(dead_code)]` on by default

warning: methods `find_closed` and `get` are never used
  --> src/main.rs:29:8
   |
13 | / impl<F, T> SegmentTree<F, T> where
14 | | T: std::fmt::Debug + Copy,
15 | | F: Fn(T, T) -> T
   | |________________- methods in this implementation
...
29 |       fn find_closed(&self, l: usize, r: usize) -> T {
   |          ^^^^^^^^^^^
...
46 |       fn get(&mut self, pos: usize) -> T {
   |          ^^^

ソースコード

diff # 

const MOD: usize = 998244353;

#[derive(Debug, Clone)]
struct SegmentTree<F, T> {
    n: usize,
    orgn: usize,
    unit: T,
    mem: Vec<T>,
    operator: F
}

impl<F, T> SegmentTree<F, T> where
T: std::fmt::Debug + Copy,
F: Fn(T, T) -> T
{
    fn new(n: usize, unit: T, operator: F) -> Self {
        let mut size = 1usize;
        while size < n { size *= 2; }
        Self {
            n: size,
            orgn: n,
            unit: unit,
            mem: vec![unit; size*2-1],
            operator: operator,
        }
    }

    fn find_closed(&self, l: usize, r: usize) -> T {
        self.find(l, r+1)
    }

    fn find(&self, l: usize, r: usize) -> T {
        self._find(l, r, 0, 0, self.n)
    }

    fn set(&mut self, pos: usize, val: T) {
        let mut pos = pos + self.n - 1;
        self.mem[pos] = val;
        while pos > 0 {
            pos = self._parent(pos);
            self.mem[pos] = (self.operator)(self.mem[self._left(pos)], self.mem[self._right(pos)]);
        }
    }

    fn get(&mut self, pos: usize) -> T {
        self.mem[pos + self.n - 1]
    }

    fn _find(&self, a: usize, b: usize, nodenum: usize, l: usize, r: usize) -> T {
        if r <= a || b <= l {
            return self.unit;
        } else if a <= l && r <= b {
            return self.mem[nodenum];
        }
        let left = self._find(a, b, self._left(nodenum), l, (l+r)/2);
        let right = self._find(a, b, self._right(nodenum), (l+r)/2, r);
        (self.operator)(left, right)
    }
    fn _left(&self, k: usize) -> usize {
        2*k+1
    }
    fn _right(&self, k: usize) -> usize {
        2*k+2
    }
    fn _parent(&self, k: usize) -> usize {
        (k-1)/2
    }
}

fn main() {
    let mut n = String::new();
    std::io::stdin().read_line(&mut n).ok();
    let n: usize = n.trim().parse().unwrap();
    let mut a = String::new();
    std::io::stdin().read_line(&mut a).ok();
    let a: Vec<usize> = a.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();

    let mut a = (0..n).map(|i| (a[i], i)).collect::<Vec<_>>();
    a.sort();
    let mut minvalseg = SegmentTree::new(n, 0usize, |x, y| x + y);
    let mut maxvalseg = SegmentTree::new(n, 0usize, |x, y| x + y);
    let mut mincntseg = SegmentTree::new(n, 0usize, |x, y| x + y);
    let mut maxcntseg = SegmentTree::new(n, 0usize, |x, y| x + y);
    let mut min_cnts = vec![0usize; n];
    let mut max_cnts = vec![0usize; n];
    let mut min_vals = vec![0usize; n];
    let mut max_vals = vec![0usize; n];
    for &(v, i) in a.iter() {
        min_cnts[i] = mincntseg.find(i, n);
        mincntseg.set(i, 1);
        min_vals[i] = minvalseg.find(i, n) % MOD;
        minvalseg.set(i, v);
    }
    a.reverse();
    for &(v, i) in a.iter() {
        max_cnts[i] = maxcntseg.find(0, i);
        maxcntseg.set(i, 1);
        max_vals[i] = maxvalseg.find(0, i) % MOD;
        maxvalseg.set(i, v);
    }
    let mut result = 0usize;
    for &(v, i) in a.iter() {
        result += min_cnts[i] * max_vals[i] + max_cnts[i] * min_vals[i] + v * min_cnts[i] % MOD * max_cnts[i] % MOD;
        result %= MOD;
    }
    println!("{}", result);
}
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