#703277 (Rust) No.776 A Simple RMQ Problem

• 問題: No.776 A Simple RMQ Problem
• ユーザー: koba-e964
• 提出日時: 2021-09-27 16:23:14
• 言語: Rust (1.83.0 + proconio)
• 結果: AC
• 実行時間: 430 ms / 3,000 ms
• コード長: 8,760 bytes
• コンパイル時間: 21,380 ms
• コンパイル使用メモリ: 388,424 KB
• 実行使用メモリ: 19,072 KB
• 最終ジャッジ日時: 2024-07-06 12:08:58
• 合計ジャッジ時間: 33,901 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
sample	AC * 2
other	AC * 26

ソースコード

#[allow(unused_imports)]
use std::cmp::*;
#[allow(unused_imports)]
use std::collections::*;
use std::io::Read;

#[allow(dead_code)]
fn getline() -> String {
    let mut ret = String::new();
    std::io::stdin().read_line(&mut ret).ok().unwrap();
    ret
}

fn get_word() -> String {
    let stdin = std::io::stdin();
    let mut stdin=stdin.lock();
    let mut u8b: [u8; 1] = [0];
    loop {
        let mut buf: Vec<u8> = Vec::with_capacity(16);
        loop {
            let res = stdin.read(&mut u8b);
            if res.unwrap_or(0) == 0 || u8b[0] <= b' ' {
                break;
            } else {
                buf.push(u8b[0]);
            }
        }
        if buf.len() >= 1 {
            let ret = String::from_utf8(buf).unwrap();
            return ret;
        }
    }
}

#[allow(dead_code)]
fn get<T: std::str::FromStr>() -> T { get_word().parse().ok().unwrap() }

/**
 * Segment Tree. This data structure is useful for fast folding on intervals of an array
 * whose elements are elements of monoid I. Note that constructing this tree requires the identity
 * element of I and the operation of I.
 * Verified by: yukicoder No. 259 (http://yukicoder.me/submissions/100581)
 *              AGC015-E (http://agc015.contest.atcoder.jp/submissions/1461001)
 */
struct SegTree<I, BiOp> {
    n: usize,
    dat: Vec<I>,
    op: BiOp,
    e: I,
}

impl<I, BiOp> SegTree<I, BiOp>
    where BiOp: Fn(I, I) -> I,
          I: Copy {
    pub fn new(n_: usize, op: BiOp, e: I) -> Self {
        let mut n = 1;
        while n < n_ { n *= 2; } // n is a power of 2
        SegTree {n: n, dat: vec![e; 2 * n - 1], op: op, e: e}
    }
    /* ary[k] <- v */
    pub fn update(&mut self, idx: usize, v: I) {
        let mut k = idx + self.n - 1;
        self.dat[k] = v;
        while k > 0 {
            k = (k - 1) / 2;
            self.dat[k] = (self.op)(self.dat[2 * k + 1], self.dat[2 * k + 2]);
        }
    }
    /* [a, b) (note: half-inclusive)
     * http://proc-cpuinfo.fixstars.com/2017/07/optimize-segment-tree/ */
    pub fn query(&self, mut a: usize, mut b: usize) -> I {
        let mut left = self.e;
        let mut right = self.e;
        a += self.n - 1;
        b += self.n - 1;
        while a < b {
            if (a & 1) == 0 {
                left = (self.op)(left, self.dat[a]);
            }
            if (b & 1) == 0 {
                right = (self.op)(self.dat[b - 1], right);
            }
            a = a / 2;
            b = (b - 1) / 2;
        }
        (self.op)(left, right)
    }
}

/**
 * Lazy Segment Tree. This data structure is useful for fast folding and updating on intervals of an array
 * whose elements are elements of monoid T. Note that constructing this tree requires the identity
 * element of T and the operation of T. This is monomorphised, because of efficiency. T := i64, biop = max, upop = (+)
 * Reference: http://d.hatena.ne.jp/kyuridenamida/20121114/1352835261
 * Verified by https://codeforces.com/contest/1114/submission/49759034
 */
pub trait ActionRing {
    type T: Clone + Copy; // data
    type U: Clone + Copy + PartialEq + Eq; // action
    fn biop(x: Self::T, y: Self::T) -> Self::T;
    fn update(x: Self::T, a: Self::U, height: usize) -> Self::T;
    fn upop(fst: Self::U, snd: Self::U) -> Self::U;
    fn e() -> Self::T;
    fn upe() -> Self::U; // identity for upop
}
pub struct LazySegTree<R: ActionRing> {
    n: usize,
    dep: usize,
    dat: Vec<R::T>,
    lazy: Vec<R::U>,
}

impl<R: ActionRing> LazySegTree<R> {
    #[allow(unused)]
    pub fn new(n_: usize) -> Self {
        let mut n = 1;
        let mut dep = 0;
        while n < n_ { n *= 2; dep += 1; } // n is a power of 2
        LazySegTree {
            n: n,
            dep: dep,
            dat: vec![R::e(); 2 * n - 1],
            lazy: vec![R::upe(); 2 * n - 1]
        }
    }
    #[allow(unused)]
    pub fn with(a: &[R::T]) -> Self {
        let n_ = a.len();
        let mut n = 1;
        let mut dep = 0;
        while n < n_ { n *= 2; dep += 1; } // n is a power of 2
        let mut dat = vec![R::e(); 2 * n - 1];
        for i in 0..n_ {
            dat[n - 1 + i] = a[i];
        }
        for i in (0..n - 1).rev() {
            dat[i] = R::biop(dat[2 * i + 1], dat[2 * i + 2]);
        }
        LazySegTree {
            n: n,
            dep: dep,
            dat: dat,
            lazy: vec![R::upe(); 2 * n - 1],
        }
    }
    #[inline]
    fn lazy_evaluate_node(&mut self, k: usize, height: usize) {
        if self.lazy[k] == R::upe() { return; }
        self.dat[k] = R::update(self.dat[k], self.lazy[k], height);
        if k < self.n - 1 {
            self.lazy[2 * k + 1] = R::upop(self.lazy[2 * k + 1], self.lazy[k]);
            self.lazy[2 * k + 2] = R::upop(self.lazy[2 * k + 2], self.lazy[k]);
        }
        self.lazy[k] = R::upe(); // identity for upop
    }
    #[inline]
    fn update_node(&mut self, k: usize) {
        self.dat[k] = R::biop(self.dat[2 * k + 1], self.dat[2 * k + 2]);
    }
    fn update_sub(&mut self, a: usize, b: usize, v: R::U, k: usize, height: usize, l: usize, r: usize) {
        self.lazy_evaluate_node(k, height);

        // [a,b) and  [l,r) intersects?
        if r <= a || b <= l {return;}
        if a <= l && r <= b {
            self.lazy[k] = R::upop(self.lazy[k], v);
            self.lazy_evaluate_node(k, height);
            return;
        }

        self.update_sub(a, b, v, 2 * k + 1, height - 1, l, (l + r) / 2);
        self.update_sub(a, b, v, 2 * k + 2, height - 1, (l + r) / 2, r);
        self.update_node(k);
    }
    /* ary[i] = upop(ary[i], v) for i in [a, b) (half-inclusive) */
    #[inline]
    pub fn update(&mut self, a: usize, b: usize, v: R::U) {
        let n = self.n;
        let dep = self.dep;
        self.update_sub(a, b, v, 0, dep, 0, n);
    }
    /* l,r are for simplicity */
    fn query_sub(&mut self, a: usize, b: usize, k: usize, height: usize, l: usize, r: usize) -> R::T {
        self.lazy_evaluate_node(k, height);

        // [a,b) and  [l,r) intersect?
        if r <= a || b <= l {return R::e();}
        if a <= l && r <= b {return self.dat[k];}
        let vl = self.query_sub(a, b, 2 * k + 1, height - 1, l, (l + r) / 2);
        let vr = self.query_sub(a, b, 2 * k + 2, height - 1, (l + r) / 2, r);
        self.update_node(k);
        R::biop(vl, vr)
    }
    /* [a, b) (note: half-inclusive) */
    #[inline]
    pub fn query(&mut self, a: usize, b: usize) -> R::T {
        let n = self.n;
        let dep = self.dep;
        self.query_sub(a, b, 0, dep, 0, n)
    }
}

enum AddMax {}

impl ActionRing for AddMax {
    type T = i64; // data
    type U = i64; // action, a |-> x |-> a + x
    fn biop(x: Self::T, y: Self::T) -> Self::T {
        std::cmp::max(x, y)
    }
    fn update(x: Self::T, a: Self::U, _height: usize) -> Self::T {
        x + a
    }
    fn upop(fst: Self::U, snd: Self::U) -> Self::U {
        fst + snd
    }
    fn e() -> Self::T {
        -1 << 50
    }
    fn upe() -> Self::U { // identity for upop
        0
    }
}

const INF: i64 = 1 << 50;

fn main() {
    let n: usize = get();
    let q: usize = get();
    let mut a: Vec<i64> = (0..n).map(|_| get()).collect();
    let mut acc = vec![0; n + 1];
    for i in 0..n {
        acc[i + 1] = acc[i] + a[i];
    }
    let mut stma = LazySegTree::<AddMax>::with(&acc);
    for i in 0..n + 1 {
        acc[i] = -acc[i];
    }
    let mut stmi = LazySegTree::<AddMax>::with(&acc);
    let mut st = SegTree::new(n, |(mi1, ma1, v1, d1), (mi2, ma2, v2, d2)| {
        (min(mi1, d1 + mi2), max(ma1, d1 + ma2), max(v1, max(v2, d1 + ma2 - mi1)), d1 + d2)
    }, (INF, -INF, -INF, 0));
    for i in 0..n {
        let x = a[i];
        st.update(i, (0, x, x, x));
    }
    for _ in 0..q {
        let kind = get_word();
        if kind == "set" {
            let i: usize = get();
            let x: i64 = get();
            let diff = x - a[i - 1];
            stma.update(i, n + 1, diff);
            stmi.update(i, n + 1, -diff);
            st.update(i - 1, (0, x, x, x));
            a[i - 1] = x;
        } else {
            // TODO: don't assume l2 <= r2, l1 <= r1
            let l1 = get::<usize>() - 1;
            let l2: usize = get();
            let r1: usize = get();
            let r2 = get::<usize>() + 1;
            let l2 = min(l2, r2 - 1);
            let r1 = max(r1, l1 + 1);
            let x = min(l2, r1);
            let y = max(l2, r1);
            // eprintln!("{} {} {} {} {} {}", l1, l2, r1, r2, x, y);
            let mut tmp = stma.query(r1, r2) + stmi.query(l1, x);
            tmp = max(tmp, stma.query(y, r2) + stmi.query(l1, l2));
            if l2 > r1 {
                tmp = max(tmp, st.query(x, y).2);
            }
            println!("{}", tmp);
        }
    }
}