#305093 (Rust) No.770 Median Sequence

• 問題: No.770 Median Sequence
• ユーザー: koba-e964
• 提出日時: 2018-12-19 00:28:53
• 言語: Rust (1.77.0)
• 結果: CE (最新)
  AC
  (最初)
• 実行時間: -
• コード長: 8,457 bytes
• コンパイル時間: 430 ms
• コンパイル使用メモリ: 156,796 KB
• 最終ジャッジ日時: 2023-10-25 23:46:44
• 合計ジャッジ時間: 776 ms
• ジャッジサーバーID （参考情報）: judge12 / judge11

コンパイルメッセージ

error[E0502]: cannot borrow `dp2` as immutable because it is also borrowed as mutable
   --> Main.rs:268:23
    |
267 |                   dp2[i][j] += dp[i - turn][j + 1]
    |                   ---
    |                   |
    |  _________________mutable borrow occurs here
    | |
268 | |                     + dp2[i - 1][j + 1];
    | |_______________________^^^_____________- mutable borrow later used here
    |                         |
    |                         immutable borrow occurs here
    |
help: try adding a local storing this...
   --> Main.rs:268:23
    |
268 |                     + dp2[i - 1][j + 1];
    |                       ^^^^^^^^^^
help: ...and then using that local here
   --> Main.rs:267:17
    |
267 | /                 dp2[i][j] += dp[i - turn][j + 1]
268 | |                     + dp2[i - 1][j + 1];
    | |_______________________________________^

error[E0502]: cannot borrow `dp2` as immutable because it is also borrowed as mutable
   --> Main.rs:269:30
    |
269 |                 dp2[i][j] += dp2[i - 1][j];
    |                 -------------^^^----------
    |                 |            |
    |                 |            immutable borrow occurs here
    |                 mutable borrow occurs here
    |                 mutable borrow later used here
    |
help: try adding a local storing this...
   --> Main.rs:269:30
    |
269 |                 dp2[i][j] += dp2[i - 1][j];
    |                              ^^^^^^^^^^
help: ...and then using that local here
   --> Main.rs:269:17
    |
269 |                 dp2[i][j] += dp2[i - 1][j];
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0502`.

ソースコード

#[allow(unused_imports)]
use std::cmp::*;
#[allow(unused_imports)]
use std::collections::*;
use std::io::{Write, BufWriter};
// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        let mut next = || { iter.next().unwrap() };
        input_inner!{next, $($r)*}
    };
    ($($r:tt)*) => {
        let stdin = std::io::stdin();
        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
        let mut next = move || -> String{
            bytes
                .by_ref()
                .map(|r|r.unwrap() as char)
                .skip_while(|c|c.is_whitespace())
                .take_while(|c|!c.is_whitespace())
                .collect()
        };
        input_inner!{next, $($r)*}
    };
}

macro_rules! input_inner {
    ($next:expr) => {};
    ($next:expr, ) => {};

    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };
}

macro_rules! read_value {
    ($next:expr, ( $($t:tt),* )) => {
        ( $(read_value!($next, $t)),* )
    };

    ($next:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    };

    ($next:expr, chars) => {
        read_value!($next, String).chars().collect::<Vec<char>>()
    };

    ($next:expr, usize1) => {
        read_value!($next, usize) - 1
    };

    ($next:expr, [ $t:tt ]) => {{
        let len = read_value!($next, usize);
        (0..len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    }};

    ($next:expr, $t:ty) => {
        $next().parse::<$t>().expect("Parse error")
    };
}

/// Verified by: https://beta.atcoder.jp/contests/arc099/submissions/3515280
mod mod_int {
    use std::ops::*;
    pub trait Mod: Copy + Clone {
        fn m() -> i64;
    }
    #[derive(Copy, Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]
    pub struct ModInt<M: Mod> { pub x: i64, phantom: ::std::marker::PhantomData<*const M> }
    impl<M: Mod> ModInt<M> {
        fn check_integrity(self) {
            debug_assert!(self.x >= 0);
            debug_assert!(self.x < M::m());
        }
        // x >= 0
        pub fn new(x: i64) -> Self { ModInt::new_internal(x % M::m()) }
        fn new_internal(x: i64) -> Self { ModInt { x: x, phantom: ::std::marker::PhantomData } }
        #[allow(dead_code)]
        pub fn mul_fast(self, other: Self) -> Self {
            self.check_integrity();
            other.check_integrity();
            ModInt::new_internal(self.x * other.x % M::m())
        }
        #[allow(dead_code)]
        pub fn mul_slow(self, other: Self) -> Self {
            // Naive multiplication in order to avoid overflow
            self.check_integrity();
            other.check_integrity();
            let mut sum = ModInt::new_internal(0);
            let mut cur = self;
            let mut e = other.x;
            if self.x < other.x {
                cur = other;
                e = self.x;
            }
            while e > 0 {
                if e % 2 == 1 {
                    sum += cur;
                }
                cur += cur;
                e /= 2;
            }
            sum
        }
        pub fn pow(self, mut e: i64) -> Self {
            self.check_integrity();
            debug_assert!(e >= 0);
            let mut sum = ModInt::new_internal(1);
            let mut cur = self;
            while e > 0 {
                if e % 2 != 0 {
                    sum *= cur;
                }
                cur *= cur;
                e /= 2;
            }
            sum
        }
        #[allow(dead_code)]
        pub fn inv(self) -> Self { self.pow(M::m() - 2) }
    }
    impl<M: Mod> Add for ModInt<M> {
        type Output = Self;
        fn add(self, other: Self) -> Self {
            self.check_integrity();
            other.check_integrity();
            let mut sum = self.x + other.x;
            if sum >= M::m() { sum -= M::m(); }
            ModInt::new_internal(sum)
        }
    }
    impl<M: Mod> Sub for ModInt<M> {
        type Output = Self;
        fn sub(self, other: Self) -> Self {
            self.check_integrity();
            other.check_integrity();
            let mut sum = self.x - other.x;
            if sum < 0 { sum += M::m(); }
            ModInt::new_internal(sum)
        }
    }
    impl<M: Mod> Mul for ModInt<M> {
        type Output = Self;
        fn mul(self, other: Self) -> Self {
            self.mul_fast(other)
        }
    }
    impl<M: Mod> AddAssign for ModInt<M> {
        fn add_assign(&mut self, other: Self) {
            *self = *self + other;
        }
    }
    impl<M: Mod> SubAssign for ModInt<M> {
        fn sub_assign(&mut self, other: Self) {
            *self = *self - other;
        }
    }
    impl<M: Mod> MulAssign for ModInt<M> {
        fn mul_assign(&mut self, other: Self) {
            *self = *self * other;
        }
    }
    impl<M: Mod> ::std::fmt::Display for ModInt<M> {
        fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
            self.x.fmt(f)
        }
    }
    impl<M: Mod> ::std::fmt::Debug for ModInt<M> {
        fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
            self.x.fmt(f)
        }
    }
} // mod mod_int

macro_rules! define_mod {
    ($struct_name: ident, $modulo: expr) => {
        #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
        struct $struct_name {}
        impl mod_int::Mod for $struct_name { fn m() -> i64 { $modulo } }
    }
}
const MOD: i64 = 1_000_000_007;
define_mod!(P, MOD);
type ModInt = mod_int::ModInt<P>;

fn med(a: usize, b: usize, c: usize) -> usize {
    let mut b = vec![a, b, c];
    b.sort();
    b[1]
}

fn dfs(n: usize, v: usize, b: &mut Vec<usize>, hs: &mut HashSet<Vec<usize>>) {
    if v >= n {
        let mut a = vec![0; n];
        for i in 0 .. n {
            let mut tmp = 0;
            for j in 0 .. i + 1 {
                tmp = med(tmp, b[j], n - 1 - i + j);
            }
            a[i] = tmp;
        }
        hs.insert(a);
        return;
    }
    for i in 0 .. n {
        b.push(i);
        dfs(n, v + 1, b, hs);
        b.pop();
    }
}

fn brute(n: usize) {
    let mut hs: HashSet<Vec<usize>> = HashSet::new();
    dfs(n, 0, &mut Vec::new(), &mut hs);
    println!("size = {}", hs.len());
    let mut last = vec![0; n];
    let mut cut = HashSet::new();
    let mut targ = HashSet::new();
    for mut v in hs {
        last[v[n - 1]] += 1;
        let mut hit = false;
        if v[2] == 3 && v[3] == 2 {
            targ.insert(v[0 .. 4].to_vec());
            hit = true;
        }
        if v[n - 1] == 1 {
            println!(" {:?} {}", v, if hit { "hit" } else { "" });
            v.pop();
            cut.insert(v);
        }
    }
    eprintln!("last = {:?}", last);
    for c in targ {
        eprintln!(" targ {:?}", c);
    }
}


fn solve() {
    let out = std::io::stdout();
    let mut out = BufWriter::new(out.lock());
    macro_rules! puts {
        ($format:expr) => (write!(out,$format).unwrap());
        ($format:expr, $($args:expr),+) => (write!(out,$format,$($args),*).unwrap())
    }
    input! {
        n: usize,
    }
    // brute(n);
    let mut dp = vec![vec![ModInt::new(0); n]; n + 1];
    let mut dp2 = vec![vec![ModInt::new(0); n]; n + 1];
    dp[0][0] = ModInt::new(1);
    for i in 1 .. n + 1 {
        let mut cur = ModInt::new(0);
        for j in 0 .. n {
            cur += dp[i - 1][j];
            // eprintln!("i = {}, j = {}, cur = {}", i, j, cur);
            dp[i][j] += cur;
            cur += dp2[i - 1][j];
        }
        for j in 0 .. n - 1 {
            let turn = n - 1 - j;
            if i >= turn {
                dp2[i][j] += dp[i - turn][j + 1]
                    + dp2[i - 1][j + 1];
                dp2[i][j] += dp2[i - 1][j];
            }
        }
    }
    if false {
        for i in 0 .. n + 1 {
            eprintln!("dp[{}] = {:?}", i, dp[i]);
            eprintln!("dp2[{}] = {:?}", i, dp2[i]);
        }
    }
    let mut tot = ModInt::new(0);
    for i in 0 .. n { tot += dp2[n][i] + dp[n][i]; }
    puts!("{}\n", tot);
}

fn main() {
    // In order to avoid potential stack overflow, spawn a new thread.
    let stack_size = 104_857_600; // 100 MB
    let thd = std::thread::Builder::new().stack_size(stack_size);
    thd.spawn(|| solve()).unwrap().join().unwrap();
}