#977206 (Rust) No.2741 Balanced Choice

• 問題: No.2741 Balanced Choice
• ユーザー: naut
• 提出日時: 2024-04-25 02:27:59
• 言語: Rust (1.77.0)
• 結果: AC
• 実行時間: 42 ms / 2,000 ms
• コード長: 5,833 bytes
• コンパイル時間: 1,046 ms
• コンパイル使用メモリ: 160,368 KB
• 実行使用メモリ: 5,376 KB
• 最終ジャッジ日時: 2024-04-25 02:28:04
• 合計ジャッジ時間: 2,139 ms
• ジャッジサーバーID （参考情報）: judge1 / judge4

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	41 ms; 5,248 KB
testcase_01	AC	42 ms; 5,248 KB
testcase_02	AC	42 ms; 5,376 KB
testcase_03	AC	42 ms; 5,376 KB
testcase_04	AC	42 ms; 5,376 KB
testcase_05	AC	1 ms; 5,376 KB
testcase_06	AC	1 ms; 5,376 KB
testcase_07	AC	21 ms; 5,376 KB
testcase_08	AC	34 ms; 5,376 KB
testcase_09	AC	19 ms; 5,376 KB
testcase_10	AC	24 ms; 5,376 KB
testcase_11	AC	35 ms; 5,376 KB

ソースコード

#![allow(non_snake_case, unused_imports, unused_must_use)]
use std::io::{self, prelude::*};

fn main() {
    let (stdin, stdout) = (io::stdin(), io::stdout());
    let mut scan = Scanner::new(stdin.lock());
    let mut out = io::BufWriter::new(stdout.lock());

    macro_rules! input {
        ($T: ty) => {
            scan.token::<$T>()
        };
        ($T: ty, $N: expr) => {
            (0..$N).map(|_| scan.token::<$T>()).collect::<Vec<_>>()
        };
    }

    let N = input!(usize);
    let W = input!(usize);
    let D = input!(usize);

    let mut dp0 = vec![isize::MIN; W + 1];
    let mut dp1 = vec![isize::MIN; W + 1];
    dp0[0] = 0;
    dp1[0] = 0;

    for _ in 0..N {
        let t = input!(u8);
        let w = input!(usize);
        let v = input!(isize);

        if t == 0 {
            for i in (0..=W).rev() {
                if i + w <= W && dp0[i] != isize::MIN {
                    dp0[i + w] = std::cmp::max(dp0[i + w], dp0[i] + v);
                }
            }
        } else {
            for i in (0..=W).rev() {
                if i + w <= W && dp1[i] != isize::MIN {
                    dp1[i + w] = std::cmp::max(dp1[i + w], dp1[i] + v);
                }
            }
        }
    }

    let dp1 = SegmentTree::from(&dp1, |&x, &y| std::cmp::max(x, y), isize::MIN);

    let mut ans = 0;

    for i in 0..=W {
        if dp0[i] == isize::MIN {
            continue;
        }

        // 0 の重量は i
        // 1 の重量 j は i + j <= W and |i - j| <= D を満たす

        // i >= j
        let left = std::cmp::max(i as isize - D as isize, 0) as usize;
        let right = std::cmp::min(W - i, i);
        ans = std::cmp::max(ans, dp0[i] + dp1.prod(left..=right));

        // j > i
        let left = i + 1;
        let right = std::cmp::min(W - i, D + i);
        ans = std::cmp::max(ans, dp0[i] + dp1.prod(left..=right));
    }

    writeln!(out, "{}", ans);
}

pub struct SegmentTree<M> {
    size: usize,
    tree: Vec<M>,
    op: fn(&M, &M) -> M,
    id: M,
}

impl<M: Copy + PartialEq> SegmentTree<M> {
    /// self = [id; size], self.op = op, self.id = id
    pub fn new(size: usize, op: fn(&M, &M) -> M, id: M) -> Self {
        return Self {
            size: size,
            tree: vec![id; 2 * size],
            op: op,
            id: id,
        };
    }

    /// self = arr, self.op = op, self.id = id
    pub fn from(arr: &[M], op: fn(&M, &M) -> M, id: M) -> Self {
        let size = arr.len();
        let mut tree = vec![id; 2 * size];

        for i in 0..size {
            tree[i + size] = arr[i];

            assert!(op(&id, &arr[i]) == arr[i]);
        }

        for i in (1..size).rev() {
            tree[i] = op(&tree[i << 1], &tree[i << 1 | 1]);
        }

        return Self {
            size: size,
            tree: tree,
            op: op,
            id: id,
        };
    }

    /// self[pos] <- value
    pub fn insert(&mut self, mut pos: usize, value: M) -> () {
        pos += self.size;
        self.tree[pos] = value;

        while pos > 1 {
            pos >>= 1;
            self.tree[pos] = (self.op)(&self.tree[pos << 1], &self.tree[pos << 1 | 1]);
        }
    }

    /// return self[pos]
    pub fn get_point(&self, pos: usize) -> M {
        return self[pos];
    }

    /// return Π_{i ∈ [left, right)} self[i]
    pub fn get(&self, left: usize, right: usize) -> M {
        let (mut l, mut r) = (left + self.size, right + self.size);
        let (mut vl, mut vr) = (self.id, self.id);

        while l < r {
            if l & 1 == 1 {
                vl = (self.op)(&vl, &self.tree[l]);
                l += 1;
            }

            if r & 1 == 1 {
                r -= 1;
                vr = (self.op)(&self.tree[r], &vr);
            }

            l >>= 1;
            r >>= 1;
        }

        return (self.op)(&vl, &vr);
    }

    /// return Π_{i ∈ range} self[i]
    pub fn prod<R: std::ops::RangeBounds<usize>>(&self, range: R) -> M {
        let left = match range.start_bound() {
            std::ops::Bound::Included(&l) => l,
            std::ops::Bound::Excluded(&l) => l + 1,
            std::ops::Bound::Unbounded => 0,
        };

        let right = match range.end_bound() {
            std::ops::Bound::Included(&r) => r + 1,
            std::ops::Bound::Excluded(&r) => r,
            std::ops::Bound::Unbounded => self.size,
        };

        return self.get(left, right);
    }
}

impl<M> std::ops::Index<usize> for SegmentTree<M> {
    type Output = M;
    fn index(&self, index: usize) -> &Self::Output {
        &self.tree[index + self.size]
    }
}

impl<M: std::fmt::Display> std::fmt::Display for SegmentTree<M> {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(
            f,
            "{}",
            self.tree[self.size..]
                .iter()
                .map(|x| x.to_string())
                .collect::<Vec<_>>()
                .join(" ")
        )
    }
}

struct Scanner<R> {
    reader: R,
    buf_str: Vec<u8>,
    buf_iter: std::str::SplitWhitespace<'static>,
}
impl<R: BufRead> Scanner<R> {
    fn new(reader: R) -> Self {
        Self {
            reader,
            buf_str: vec![],
            buf_iter: "".split_whitespace(),
        }
    }
    fn token<T: std::str::FromStr>(&mut self) -> T {
        loop {
            if let Some(token) = self.buf_iter.next() {
                return token.parse().ok().expect("Failed parse");
            }
            self.buf_str.clear();
            self.reader
                .read_until(b'\n', &mut self.buf_str)
                .expect("Failed read");
            self.buf_iter = unsafe {
                let slice = std::str::from_utf8_unchecked(&self.buf_str);
                std::mem::transmute(slice.split_whitespace())
            }
        }
    }
}