#658590 (Rust) No.1200 お菓子配り-3

• 問題: No.1200 お菓子配り-3
• ユーザー: akakimidori
• 提出日時: 2021-05-19 13:37:18
• 言語: Rust (1.77.0)
• 結果: AC
• 実行時間: 113 ms / 4,000 ms
• コード長: 5,283 bytes
• コンパイル時間: 1,594 ms
• コンパイル使用メモリ: 177,432 KB
• 実行使用メモリ: 6,944 KB
• 最終ジャッジ日時: 2024-04-17 23:54:58
• 合計ジャッジ時間: 2,578 ms
• ジャッジサーバーID （参考情報）: judge5 / judge4

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	1 ms; 6,816 KB
testcase_01	AC	1 ms; 6,940 KB
testcase_02	AC	1 ms; 6,944 KB
testcase_03	AC	1 ms; 6,944 KB
testcase_04	AC	1 ms; 6,944 KB
testcase_05	AC	1 ms; 6,944 KB
testcase_06	AC	1 ms; 6,940 KB
testcase_07	AC	1 ms; 6,940 KB
testcase_08	AC	1 ms; 6,940 KB
testcase_09	AC	1 ms; 6,940 KB
testcase_10	AC	1 ms; 6,940 KB
testcase_11	AC	1 ms; 6,940 KB
testcase_12	AC	3 ms; 6,944 KB
testcase_13	AC	4 ms; 6,940 KB
testcase_14	AC	3 ms; 6,944 KB
testcase_15	AC	3 ms; 6,940 KB
testcase_16	AC	3 ms; 6,940 KB
testcase_17	AC	8 ms; 6,944 KB
testcase_18	AC	10 ms; 6,940 KB
testcase_19	AC	3 ms; 6,944 KB
testcase_20	AC	20 ms; 6,940 KB
testcase_21	AC	20 ms; 6,940 KB
testcase_22	AC	23 ms; 6,944 KB
testcase_23	AC	19 ms; 6,940 KB
testcase_24	AC	20 ms; 6,940 KB
testcase_25	AC	19 ms; 6,944 KB
testcase_26	AC	20 ms; 6,940 KB
testcase_27	AC	1 ms; 6,944 KB
testcase_28	AC	113 ms; 6,944 KB
testcase_29	AC	25 ms; 6,940 KB
testcase_30	AC	27 ms; 6,944 KB
testcase_31	AC	1 ms; 6,944 KB
testcase_32	AC	1 ms; 6,940 KB

ソースコード

// ---------- begin enumerate prime ----------
fn enumerate_prime<F>(n: usize, mut f: F)
where
    F: FnMut(usize),
{
    assert!(1 <= n && n <= 5 * 10usize.pow(8));
    let batch = (n as f64).sqrt().ceil() as usize;
    let mut is_prime = vec![true; batch + 1];
    for i in (2..).take_while(|p| p * p <= batch) {
        if is_prime[i] {
            let mut j = i * i;
            while let Some(p) = is_prime.get_mut(j) {
                *p = false;
                j += i;
            }
        }
    }
    let mut prime = vec![];
    for (i, p) in is_prime.iter().enumerate().skip(2) {
        if *p && i <= n {
            f(i);
            prime.push(i);
        }
    }
    let mut l = batch + 1;
    while l <= n {
        let r = std::cmp::min(l + batch, n + 1);
        is_prime.clear();
        is_prime.resize(r - l, true);
        for &p in prime.iter() {
            let mut j = (l + p - 1) / p * p - l;
            while let Some(is_prime) = is_prime.get_mut(j) {
                *is_prime = false;
                j += p;
            }
        }
        for (i, _) in is_prime.iter().enumerate().filter(|p| *p.1) {
            f(i + l);
        }
        l += batch;
    }
}
// ---------- end enumerate prime ----------
// ---------- begin Exact Division ----------
// reference: https://min-25.hatenablog.com/entry/2017/08/20/171214
pub struct ExactDivision {
    a: u64,
    b: u64,
    shift: u32,
}

impl ExactDivision {
    pub fn new(d: u64) -> Self {
        assert!(d > 0);
        let shift = d.trailing_zeros();
        let d = d >> shift;
        let mut m = d;
        for _ in 0..5 {
            m *= 2 - d * m;
        }
        Self {
            a: !0 / d,
            b: m,
            shift: shift,
        }
    }
    pub fn division(&self, val: u64) -> Option<u64> {
        if val & ((1 << self.shift) - 1) != 0 {
            return None;
        }
        let res = (val >> self.shift) * self.b;
        if res <= self.a {
            Some(res)
        } else {
            None
        }
    }
}
// ---------- end Exact Division ----------
// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

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

macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, bytes) => {
        read_value!($iter, String).bytes().collect::<Vec<u8>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}
// ---------- end input macro ----------

use std::io::Write;

fn run() {
    input! {
        t: usize,
        ask: [(u64, u64); t],
    }
    let m = 10f64.powi(9).sqrt().ceil() as usize;
    let mut exact = vec![];
    enumerate_prime(m, |p| exact.push((p as u64, ExactDivision::new(p as u64))));
    let divisor = |mut n: u64| -> Vec<u64> {
        let mut d = vec![1];
        for &(p, ref e) in exact.iter() {
            if p * p > n {
                break;
            }
            let mut c = 0;
            while let Some(v) = e.division(n) {
                n = v;
                c += 1;
            }
            let len = d.len();
            let mut m = 1;
            for _ in 1..=c {
                m *= p;
                for i in 0..len {
                    let v = d[i] * m;
                    d.push(v);
                }
            }
        }
        if n > 1 {
            for i in 0..d.len() {
                let v = d[i] * n;
                d.push(v);
            }
        }
        d
    };
    let out = std::io::stdout();
    let mut out = std::io::BufWriter::new(out.lock());
    for (x, y) in ask {
        let mut ans = 0;
        for d in divisor(x + y) {
            if d == 1 {
                continue;
            }
            let sum = (x + y) / d;
            if sum <= 1 {
                continue;
            }
            let a = d - 1;
            if a == 1 {
                if x == y {
                    ans += sum - 1;
                }
            } else if x > sum && y > sum {
                let b = (x - sum) / (a - 1);
                let c = (y - sum) / (a - 1);
                if a * b + c == x && a * c + b == y {
                    ans += 1;
                }
            }
        }
        writeln!(out, "{}", ans).ok();
    }
}

fn main() {
    run();
}