結果

問題 No.702 中央値を求めよ LIMITED
コンテスト
ユーザー hatoo
提出日時 2018-08-05 15:03:34
言語 Rust
(1.83.0 + proconio)
結果
AC  
実行時間 1,216 ms / 5,000 ms
コード長 9,512 bytes
コンパイル時間 12,332 ms
コンパイル使用メモリ 386,244 KB
実行使用メモリ 21,504 KB
最終ジャッジ日時 2024-11-22 22:35:03
合計ジャッジ時間 46,613 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge4
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 * 2
other AC * 25
権限があれば一括ダウンロードができます

ソースコード

diff # 

#[doc = " https://github.com/hatoo/competitive-rust-snippets"]
#[allow(unused_imports)]
use std::cmp::{max, min, Ordering};
#[allow(unused_imports)]
use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, VecDeque};
#[allow(unused_imports)]
use std::io::{stdin, stdout, BufWriter, Write};
#[allow(unused_imports)]
use std::iter::FromIterator;
mod util {
    use std::fmt::Debug;
    use std::io::{stdin, stdout, BufWriter, StdoutLock};
    use std::str::FromStr;
    #[allow(dead_code)]
    pub fn line() -> String {
        let mut line: String = String::new();
        stdin().read_line(&mut line).unwrap();
        line.trim().to_string()
    }
    #[allow(dead_code)]
    pub fn chars() -> Vec<char> {
        line().chars().collect()
    }
    #[allow(dead_code)]
    pub fn gets<T: FromStr>() -> Vec<T>
    where
        <T as FromStr>::Err: Debug,
    {
        let mut line: String = String::new();
        stdin().read_line(&mut line).unwrap();
        line.split_whitespace()
            .map(|t| t.parse().unwrap())
            .collect()
    }
    #[allow(dead_code)]
    pub fn with_bufwriter<F: FnOnce(BufWriter<StdoutLock>) -> ()>(f: F) {
        let out = stdout();
        let writer = BufWriter::new(out.lock());
        f(writer)
    }
}
#[allow(unused_macros)]
macro_rules ! get { ( $ t : ty ) => { { let mut line : String = String :: new ( ) ; stdin ( ) . read_line ( & mut line ) . unwrap ( ) ; line . trim ( ) . parse ::<$ t > ( ) . unwrap ( ) } } ; ( $ ( $ t : ty ) ,* ) => { { let mut line : String = String :: new ( ) ; stdin ( ) . read_line ( & mut line ) . unwrap ( ) ; let mut iter = line . split_whitespace ( ) ; ( $ ( iter . next ( ) . unwrap ( ) . parse ::<$ t > ( ) . unwrap ( ) , ) * ) } } ; ( $ t : ty ; $ n : expr ) => { ( 0 ..$ n ) . map ( | _ | get ! ( $ t ) ) . collect ::< Vec < _ >> ( ) } ; ( $ ( $ t : ty ) ,*; $ n : expr ) => { ( 0 ..$ n ) . map ( | _ | get ! ( $ ( $ t ) ,* ) ) . collect ::< Vec < _ >> ( ) } ; ( $ t : ty ;; ) => { { let mut line : String = String :: new ( ) ; stdin ( ) . read_line ( & mut line ) . unwrap ( ) ; line . split_whitespace ( ) . map ( | t | t . parse ::<$ t > ( ) . unwrap ( ) ) . collect ::< Vec < _ >> ( ) } } ; ( $ t : ty ;; $ n : expr ) => { ( 0 ..$ n ) . map ( | _ | get ! ( $ t ;; ) ) . collect ::< Vec < _ >> ( ) } ; }
#[allow(unused_macros)]
macro_rules ! debug { ( $ ( $ a : expr ) ,* ) => { eprintln ! ( concat ! ( $ ( stringify ! ( $ a ) , " = {:?}, " ) ,* ) , $ ( $ a ) ,* ) ; } }
const BIG_STACK_SIZE: bool = false;
#[allow(dead_code)]
fn main() {
    use std::thread;
    if BIG_STACK_SIZE {
        thread::Builder::new()
            .stack_size(64 * 1024 * 1024)
            .name("solve".into())
            .spawn(solve)
            .unwrap()
            .join()
            .unwrap();
    } else {
        solve();
    }
}

struct XorShift {
    x: u32,
    y: u32,
    z: u32,
    w: u32,
}

impl XorShift {
    fn new(x: u32) -> XorShift {
        XorShift {
            x,
            y: 1,
            z: 2,
            w: 3,
        }
    }

    fn next(&mut self) -> u32 {
        let t = self.x ^ (self.x << 11);
        self.x = self.y;
        self.y = self.z;
        self.z = self.w;
        self.w = (self.w ^ (self.w >> 19)) ^ (t ^ (t >> 8));
        self.w
    }
}

#[doc = " IntervalHeap"]
#[derive(Clone, Debug)]
struct IntervalHeap<T: Ord + Eq> {
    data: Vec<T>,
}
impl<T: Ord + Eq> IntervalHeap<T> {
    #[allow(dead_code)]
    fn new() -> IntervalHeap<T> {
        IntervalHeap { data: Vec::new() }
    }
    #[allow(dead_code)]
    fn with_capacity(n: usize) -> IntervalHeap<T> {
        IntervalHeap {
            data: Vec::with_capacity(n),
        }
    }
    #[allow(dead_code)]
    #[inline]
    fn len(&self) -> usize {
        self.data.len()
    }
    #[allow(dead_code)]
    #[inline]
    fn is_empty(&self) -> bool {
        self.data.is_empty()
    }
    #[allow(dead_code)]
    #[inline]
    fn push(&mut self, x: T) {
        let i = self.data.len();
        self.data.push(x);
        self.up(i);
    }
    #[allow(dead_code)]
    #[inline]
    fn peek_min(&self) -> Option<&T> {
        self.data.first()
    }
    #[allow(dead_code)]
    #[inline]
    fn peek_max(&self) -> Option<&T> {
        if self.data.len() > 1 {
            self.data.get(1)
        } else {
            self.data.first()
        }
    }
    #[allow(dead_code)]
    #[inline]
    fn pop_min(&mut self) -> Option<T> {
        if self.data.len() == 1 {
            return self.data.pop();
        }
        if self.data.is_empty() {
            return None;
        }
        let len = self.data.len();
        self.data.swap(0, len - 1);
        let res = self.data.pop();
        self.down(0);
        res
    }
    #[allow(dead_code)]
    #[inline]
    fn pop_max(&mut self) -> Option<T> {
        if self.data.len() <= 2 {
            return self.data.pop();
        }
        if self.data.is_empty() {
            return None;
        }
        let len = self.data.len();
        self.data.swap(1, len - 1);
        let res = self.data.pop();
        self.down(1);
        res
    }
    #[allow(dead_code)]
    #[inline]
    fn parent(i: usize) -> usize {
        ((i >> 1) - 1) & !1
    }
    #[allow(dead_code)]
    #[inline]
    fn down(&mut self, i: usize) {
        let mut i = i;
        let n = self.data.len();
        if i & 1 == 0 {
            while (i << 1) + 2 < n {
                let mut k = (i << 1) + 2;
                if k + 2 < n
                    && unsafe { self.data.get_unchecked(k + 2) }
                        < unsafe { self.data.get_unchecked(k) }
                {
                    k = k + 2;
                }
                if unsafe { self.data.get_unchecked(i) } > unsafe { self.data.get_unchecked(k) } {
                    self.data.swap(i, k);
                    i = k;
                    if i + 1 < self.data.len()
                        && unsafe { self.data.get_unchecked(i) }
                            > unsafe { self.data.get_unchecked(i + 1) }
                    {
                        self.data.swap(i, i + 1);
                    }
                } else {
                    break;
                }
            }
        } else {
            while (i << 1) + 1 < n {
                let mut k = (i << 1) + 1;
                if k + 2 < n
                    && unsafe { self.data.get_unchecked(k + 2) }
                        > unsafe { self.data.get_unchecked(k) }
                {
                    k = k + 2;
                }
                if unsafe { self.data.get_unchecked(i) } < unsafe { self.data.get_unchecked(k) } {
                    self.data.swap(i, k);
                    i = k;
                    if i > 0
                        && unsafe { self.data.get_unchecked(i) }
                            < unsafe { self.data.get_unchecked(i - 1) }
                    {
                        self.data.swap(i, i - 1);
                    }
                } else {
                    break;
                }
            }
        }
    }
    #[allow(dead_code)]
    #[inline]
    fn up(&mut self, i: usize) {
        let mut i = i;
        if i & 1 == 1
            && unsafe { self.data.get_unchecked(i) } < unsafe { self.data.get_unchecked(i - 1) }
        {
            self.data.swap(i, i - 1);
            i -= 1;
        }
        while i > 1
            && unsafe { self.data.get_unchecked(i) }
                < unsafe { self.data.get_unchecked(Self::parent(i)) }
        {
            let p = Self::parent(i);
            self.data.swap(i, p);
            i = p;
        }
        while i > 1
            && unsafe { self.data.get_unchecked(i) }
                > unsafe { self.data.get_unchecked(Self::parent(i) + 1) }
        {
            let p = Self::parent(i) + 1;
            self.data.swap(i, p);
            i = p;
        }
    }
    #[allow(dead_code)]
    #[inline]
    fn clear(&mut self) {
        self.data.clear();
    }
}
#[derive(Clone, Debug)]
struct LimitedIntervalHeap<T: Ord + Eq> {
    heap: IntervalHeap<T>,
    limit: usize,
}
impl<T: Ord + Eq> LimitedIntervalHeap<T> {
    #[allow(dead_code)]
    fn new(limit: usize) -> LimitedIntervalHeap<T> {
        LimitedIntervalHeap {
            heap: IntervalHeap::with_capacity(limit),
            limit: limit,
        }
    }
    #[allow(dead_code)]
    #[inline]
    fn is_empty(&self) -> bool {
        self.heap.is_empty()
    }
    #[allow(dead_code)]
    #[inline]
    fn push(&mut self, x: T) -> Option<T> {
        if self.heap.len() < self.limit {
            self.heap.push(x);
            None
        } else {
            if self.heap.data[0] < x {
                let mut x = x;
                std::mem::swap(&mut x, &mut self.heap.data[0]);
                if self.heap.len() >= 2 && self.heap.data[0] > self.heap.data[1] {
                    self.heap.data.swap(0, 1);
                }
                self.heap.down(0);
                Some(x)
            } else {
                Some(x)
            }
        }
    }
    #[allow(dead_code)]
    #[inline]
    fn pop(&mut self) -> Option<T> {
        self.heap.pop_max()
    }
    #[allow(dead_code)]
    #[inline]
    fn clear(&mut self) {
        self.heap.clear();
    }
}

fn solve() {
    let seed = get!(u32);

    let mut rng = XorShift::new(seed);
    let mut heap = LimitedIntervalHeap::new(5000001);

    for _ in 0..10000001 {
        let v = rng.next();
        heap.push(v);
    }

    println!("{}", heap.heap.pop_min().unwrap());
}
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