#891182 (Rust) No.2382 Amidakuji M

• 問題: No.2382 Amidakuji M
• ユーザー: Moss_Local
• 提出日時: 2023-07-14 22:09:33
• 言語: Rust (1.77.0 + proconio)
• 結果: AC
• 実行時間: 20 ms / 2,000 ms
• コード長: 6,809 bytes
• コンパイル時間: 12,014 ms
• コンパイル使用メモリ: 378,308 KB
• 実行使用メモリ: 5,868 KB
• 最終ジャッジ日時: 2024-09-16 07:13:28
• 合計ジャッジ時間: 13,289 ms
• ジャッジサーバーID （参考情報）: judge1 / judge5

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	1 ms; 5,248 KB
testcase_01	AC	1 ms; 5,376 KB
testcase_02	AC	0 ms; 5,376 KB
testcase_03	AC	9 ms; 5,376 KB
testcase_04	AC	15 ms; 5,376 KB
testcase_05	AC	3 ms; 5,376 KB
testcase_06	AC	9 ms; 5,376 KB
testcase_07	AC	6 ms; 5,376 KB
testcase_08	AC	1 ms; 5,376 KB
testcase_09	AC	12 ms; 5,376 KB
testcase_10	AC	18 ms; 5,496 KB
testcase_11	AC	7 ms; 5,376 KB
testcase_12	AC	13 ms; 5,376 KB
testcase_13	AC	1 ms; 5,376 KB
testcase_14	AC	1 ms; 5,376 KB
testcase_15	AC	1 ms; 5,376 KB
testcase_16	AC	1 ms; 5,376 KB
testcase_17	AC	0 ms; 5,376 KB
testcase_18	AC	0 ms; 5,376 KB
testcase_19	AC	20 ms; 5,736 KB
testcase_20	AC	20 ms; 5,744 KB
testcase_21	AC	19 ms; 5,868 KB

コンパイルメッセージ

warning: unnecessary parentheses around method argument
   --> src/main.rs:249:24
    |
249 |         res += bit.sum((n - v[i]));
    |                        ^        ^
    |
    = note: `#[warn(unused_parens)]` on by default
help: remove these parentheses
    |
249 -         res += bit.sum((n - v[i]));
249 +         res += bit.sum(n - v[i]);
    |

warning: unused variable: `res`
   --> src/main.rs:244:13
    |
244 |     let mut res = 0;
    |             ^^^ help: if this is intentional, prefix it with an underscore: `_res`
    |
    = note: `#[warn(unused_variables)]` on by default

warning: variable does not need to be mutable
   --> src/main.rs:244:9
    |
244 |     let mut res = 0;
    |         ----^^^
    |         |
    |         help: remove this `mut`
    |
    = note: `#[warn(unused_mut)]` on by default

ソースコード

// -*- coding:utf-8-unix -*-
// #![feature(map_first_last)]
#![allow(dead_code)]
#![allow(unused_imports)]
#![allow(unused_macros)]
use std::arch::x86_64::_MM_FROUND_NEARBYINT;
// use core::num;
use std::cmp::*;
use std::fmt::*;
use std::hash::*;
use std::iter::FromIterator;
use std::*;
use std::{cmp, collections, fmt, io, iter, ops, str};
const INF: i64 = 1223372036854775807;
const UINF: usize = INF as usize;
const LINF: i64 = 2147483647;
const INF128: i128 = 1223372036854775807000000000000;
const MOD1: i64 = 1000000007;
const MOD9: i64 = 998244353;
const MOD: i64 = MOD9;
// const MOD: i64 = MOD2;
const UMOD: usize = MOD as usize;
const M_PI: f64 = 3.14159265358979323846;

// use proconio::input;
// const MOD: i64 = INF;

use cmp::Ordering::*;
use std::collections::*;

use std::io::stdin;
use std::io::stdout;
use std::io::Write;

macro_rules! p {
    ($x:expr) => {
        //if expr
        println!("{}", $x);
    };
}

macro_rules! vp {
    // vector print separate with space
    ($x:expr) => {
        println!(
            "{}",
            $x.iter()
                .map(|x| x.to_string())
                .collect::<Vec<_>>()
                .join(" ")
        );
    };
}

macro_rules! d {
    ($x:expr) => {
        println!("{:?}", $x);
    };
}
macro_rules! yn {
    ($val:expr) => {
        if $val {
            println!("Yes");
        } else {
            println!("No");
        }
    };
}

fn main() {
    solve();
}

// use str::Chars;
#[allow(dead_code)]
fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

#[allow(dead_code)]
fn readi() -> i64 {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    iter.next().unwrap().parse::<i64>().unwrap()
}

#[allow(dead_code)]
fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}
#[allow(dead_code)]
fn read_mat<T: std::str::FromStr>(n: u32) -> Vec<Vec<T>> {
    (0..n).map(|_| read_vec()).collect()
}

#[allow(dead_code)]
fn readii() -> (i64, i64) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<i64>().unwrap(),
        iter.next().unwrap().parse::<i64>().unwrap(),
    )
}

#[allow(dead_code)]
fn readiii() -> (i64, i64, i64) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<i64>().unwrap(),
        iter.next().unwrap().parse::<i64>().unwrap(),
        iter.next().unwrap().parse::<i64>().unwrap(),
    )
}
#[allow(dead_code)]
fn readuu() -> (usize, usize) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<usize>().unwrap(),
        iter.next().unwrap().parse::<usize>().unwrap(),
    )
}

#[allow(dead_code)]
fn readff() -> (f64, f64) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<f64>().unwrap(),
        iter.next().unwrap().parse::<f64>().unwrap(),
    )
}

fn readcc() -> (char, char) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<char>().unwrap(),
        iter.next().unwrap().parse::<char>().unwrap(),
    )
}

fn readuuu() -> (usize, usize, usize) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<usize>().unwrap(),
        iter.next().unwrap().parse::<usize>().unwrap(),
        iter.next().unwrap().parse::<usize>().unwrap(),
    )
}
#[allow(dead_code)]
fn readiiii() -> (i64, i64, i64, i64) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<i64>().unwrap(),
        iter.next().unwrap().parse::<i64>().unwrap(),
        iter.next().unwrap().parse::<i64>().unwrap(),
        iter.next().unwrap().parse::<i64>().unwrap(),
    )
}

#[allow(dead_code)]
fn readuuuu() -> (usize, usize, usize, usize) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<usize>().unwrap(),
        iter.next().unwrap().parse::<usize>().unwrap(),
        iter.next().unwrap().parse::<usize>().unwrap(),
        iter.next().unwrap().parse::<usize>().unwrap(),
    )
}

#[allow(dead_code)]
pub trait Monoid {
    type T: Clone;
    fn id() -> Self::T;
    fn op(a: &Self::T, b: &Self::T) -> Self::T;
}
#[allow(dead_code)]
pub enum SUM {}
impl Monoid for SUM {
    type T = usize;
    fn id() -> Self::T {
        0
    }
    fn op(a: &Self::T, b: &Self::T) -> Self::T {
        *a + *b
    }
}
#[allow(dead_code)]
/// Generic Binary Indexed Tree
pub struct BIT<M: Monoid> {
    buf: Vec<M::T>,
}
impl<M: Monoid> BIT<M> {
    #[allow(dead_code)]
    pub fn new(n: usize) -> Self {
        Self {
            buf: vec![M::id(); n + 1],
        }
    }
    #[allow(dead_code)]
    pub fn sum(&self, i: usize) -> M::T {
        let mut i = i;
        let mut s = M::id();
        while i > 0 {
            s = M::op(&s, &self.buf[i]);
            i &= i - 1;
        }
        s
    }
    #[allow(dead_code)]
    pub fn add(&mut self, i: usize, x: &M::T) {
        let mut i = i as i64;
        while i < self.buf.len() as i64 {
            let t = &mut self.buf[i as usize];
            *t = M::op(&t, x);
            i += i & -i;
        }
    }
}

// 0 ~ n -1
fn inversion_number(v: &Vec<usize>) -> usize {
    let mut res = 0;
    let n = v.len();
    let mut bit: BIT<SUM> = BIT::new(n);
    let mut res = 0 as usize;
    for i in 0..n {
        res += bit.sum((n - v[i]));
        bit.add(n - v[i], &1);
    }
    res
}

fn solve() {
    let (n, m) = readuu();
    let mut vec: Vec<usize> = read_vec();
    vec.iter_mut().for_each(|x| *x -= 1);
    let inv_num = inversion_number(&vec);
    if n == 2 {
        if inv_num % 2 != m % 2 {
            p!("-1");
            return;
        }
    }
    if m == 1 {
        p!(inv_num);
        return;
    }
    let mut ans = (inv_num + m - 1) / m * m;

    if (ans - inv_num) % 2 != 0 {
        if m % 2 == 1 {
            ans += m;
        } else {
            p!(-1);
            return;
        }
    }

    p!(ans);
    return;
}