#450597 (Rust) No.864 四方演算

• 問題: No.864 四方演算
• ユーザー: cotton_fn_
• 提出日時: 2020-03-28 17:39:44
• 言語: Rust (1.77.0)
• 結果: AC
• 実行時間: 12 ms / 1,000 ms
• コード長: 5,120 bytes
• コンパイル時間: 1,969 ms
• コンパイル使用メモリ: 161,772 KB
• 実行使用メモリ: 4,384 KB
• 最終ジャッジ日時: 2023-08-30 18:02:54
• 合計ジャッジ時間: 2,216 ms
• ジャッジサーバーID （参考情報）: judge14 / judge15

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	1 ms; 4,376 KB
testcase_01	AC	12 ms; 4,380 KB
testcase_02	AC	9 ms; 4,380 KB
testcase_03	AC	10 ms; 4,380 KB
testcase_04	AC	11 ms; 4,380 KB
testcase_05	AC	8 ms; 4,380 KB
testcase_06	AC	11 ms; 4,376 KB
testcase_07	AC	9 ms; 4,380 KB
testcase_08	AC	9 ms; 4,380 KB
testcase_09	AC	6 ms; 4,380 KB
testcase_10	AC	5 ms; 4,376 KB
testcase_11	AC	3 ms; 4,380 KB
testcase_12	AC	9 ms; 4,380 KB
testcase_13	AC	7 ms; 4,380 KB
testcase_14	AC	3 ms; 4,380 KB
testcase_15	AC	12 ms; 4,380 KB
testcase_16	AC	9 ms; 4,376 KB
testcase_17	AC	10 ms; 4,380 KB
testcase_18	AC	9 ms; 4,380 KB
testcase_19	AC	7 ms; 4,376 KB
testcase_20	AC	11 ms; 4,380 KB
testcase_21	AC	9 ms; 4,380 KB
testcase_22	AC	8 ms; 4,380 KB
testcase_23	AC	2 ms; 4,376 KB
testcase_24	AC	8 ms; 4,380 KB
testcase_25	AC	4 ms; 4,380 KB
testcase_26	AC	8 ms; 4,376 KB
testcase_27	AC	1 ms; 4,376 KB
testcase_28	AC	1 ms; 4,384 KB
testcase_29	AC	1 ms; 4,380 KB

ソースコード

#![allow(unused)]
use kyoproio::*;
use std::{
    collections::*,
    iter,
    mem::{replace, swap},
};

fn main() -> io::Result<()> {
    std::thread::Builder::new()
        .stack_size(50 * 1024 * 1024)
        .spawn(solve)?
        .join()
        .unwrap();
    Ok(())
}

fn solve() {
    let stdin = io::stdin();
    let mut kin = KInput::new(stdin.lock());
    let stdout = io::stdout();
    let mut out = io::BufWriter::new(stdout.lock());
    macro_rules! output {
        ($($args:expr),+) => { write!(&mut out, $($args),+) };
    }
    macro_rules! outputln {
        ($($args:expr),+) => { output!($($args),+); outputln!() };
        () => { output!("\n"); if cfg!(debug_assertions) { out.flush(); } }
    }

    let (n, k): (u64, u64) = kin.input();
    // ab + bc + cd + da = (a + c)(b + d)
    let mut ans = 0;
    let f = |x: u64| if x <= 2 * n {
        n.min(x - 1) - (x - 1).saturating_sub(n)
    } else {
        0
    };
    for i in (1..).take_while(|&i| i * i <= k) {
        if k % i == 0 {
            let j = k / i;
            ans += (1 + (i != j) as u64) * f(i) * f(j);
        }
    }
    outputln!("{}", ans);
}



// -----------------------------------------------------------------------------
pub mod kyoproio {
    #![warn(unused)]

    pub use std::io::{self, prelude::*};

    pub trait Input: Sized {
        fn str(&mut self) -> &str;
        fn bytes(&mut self) -> &[u8] {
            self.str().as_ref()
        }
        fn input<T: InputParse>(&mut self) -> T {
            self.input_fallible().expect("input error")
        }
        fn input_fallible<T: InputParse>(&mut self) -> Result<T> {
            T::input(self)
        }
        fn iter<T: InputParse>(&mut self) -> Iter<T, Self> {
            Iter {
                input: self,
                _t: std::marker::PhantomData,
            }
        }
        fn seq<T: InputParse, B: std::iter::FromIterator<T>>(&mut self, n: usize) -> B {
            self.iter().take(n).collect()
        }
    }
    pub struct KInput<R> {
        src: R,
        buf: String,
        pos: usize,
    }
    impl<R: BufRead> KInput<R> {
        pub fn new(src: R) -> Self {
            Self {
                src,
                buf: String::with_capacity(1024),
                pos: 0,
            }
        }
    }
    impl<R: BufRead> Input for KInput<R> {
        fn str(&mut self) -> &str {
            loop {
                if self.pos >= self.buf.len() {
                    self.pos = 0;
                    self.buf.clear();
                    if self.src.read_line(&mut self.buf).expect("io error") == 0 {
                        return &self.buf;
                    }
                }
                let range = self.pos
                    ..self.buf[self.pos..]
                        .find(|c: char| c.is_ascii_whitespace())
                        .map(|i| i + self.pos)
                        .unwrap_or_else(|| self.buf.len());
                self.pos = range.end + 1;
                if range.end > range.start {
                    return &self.buf[range];
                }
            }
        }
    }
    pub struct Iter<'a, T, I> {
        input: &'a mut I,
        _t: std::marker::PhantomData<T>,
    }
    impl<'a, T: InputParse, I: Input> Iterator for Iter<'a, T, I> {
        type Item = T;
        fn next(&mut self) -> Option<Self::Item> {
            Some(self.input.input())
        }
    }
    type Result<T> = std::result::Result<T, Box<dyn std::error::Error + 'static>>;
    pub trait InputParse: Sized {
        fn input<I: Input>(input: &mut I) -> Result<Self>;
    }
    macro_rules! input_from_str_impls {
        { $($T:ty)* } => {
            $(impl InputParse for $T {
                fn input<I: Input>(input: &mut I) -> Result<Self> {
                    input.str().parse::<$T>().map_err(|e| e.into())
                }
            })*
        };
    }
    input_from_str_impls! {
        String char bool f32 f64
        isize i8 i16 i32 i64 i128
        usize u8 u16 u32 u64 u128
    }
    macro_rules! input_tuple_impls {
        ($H:ident, $($T:ident),+) => {
            impl<$H: InputParse, $($T: InputParse),+> InputParse for ($H, $($T),+) {
                fn input<I: Input>(input: &mut I) -> Result<Self> {
                    Ok(($H::input(input)?, $($T::input(input)?),+))
                }
            }
            input_tuple_impls!($($T),+);
        };
        ($H:ident) => {};
    }
    input_tuple_impls!(A, B, C, D, E, F, G);
    /*
    impl<T: InputParse, const N: usize> InputParse for [T; N] {
        fn input<I: Input>(input: &mut I) -> Result<Self> {
            let mut a = std::mem::MaybeUninit::<[T; N]>::uninit();
            for i in 0..N {
                match T::input(input) {
                    Ok(v) => unsafe { std::ptr::write(&mut (*a.as_mut_ptr())[i], v) },
                    Err(e) => unsafe {
                        std::ptr::drop_in_place(&mut (*a.as_mut_ptr())[..i]);
                        return Err(e);
                    },
                }
            }
            Ok(unsafe { a.assume_init() })
        }
    }
    */
}