Submission #1183580

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Source Code Expand

fn main() {
    let mut sc = cin();

    let mut binom = [[0; 60]; 60];
    for i in 0..60 {
        for j in 0..60 {
            binom[i][j] = if j == 0 {
                1
            } else if i < j {
                0
            } else {
                binom[i-1][j-1] + binom[i-1][j]
            }
        }
    }

    while sc.read() {
        let n = sc.next();
        let a: usize = sc.next();
        let b: usize = sc.next();
        let mut v = sc.vec::<i64>(n);
        v.sort();
        v.reverse();
        let mut max_ave: f64 = 0.0;
        for k in a..b+1 {
            let sum: i64 = v.iter().take(k).sum();
            let ave = sum as f64 / k as f64;
            if max_ave < ave {
                max_ave = ave;
            }
        }

        println!("{:.10}", max_ave);
        let mut cnt: Vec<(usize, _)> = vec![];
        for &x in v.iter() {
            if cnt.len() == 0 || cnt.last().unwrap().1 != x {
                cnt.push((1, x));
            } else {
                cnt.last_mut().unwrap().0 += 1;
            }
        }

        let mut ans = 0u64;
        for k in a..b+1 {
            let sum: i64 = v.iter().take(k).sum();
            let ave = sum as f64 / k as f64;
            if ave != max_ave {
                continue;
            }
            let mut cur = 0;
            let mut x = 1u64;
            for &(a, _) in cnt.iter() {
                if cur <= k && k <= cur + a {
                    x *= binom[a][k - cur];
                    // println!("binom {} {}", a, k-cur);
                }
                cur += a;
            }
            ans += x;
        }
        println!("{}", ans);
    }
}

#[allow(dead_code)]
fn cin() -> Scanner<std::io::Stdin> {
    Scanner::new(std::io::stdin())
}

#[allow(dead_code)]
pub struct Scanner<T> {
    buf: Vec<u8>,
    len: usize,
    idx: usize,
    next: Option<String>,
    reader: T,
}

#[allow(dead_code)]
impl<Reader: std::io::Read> Scanner<Reader> {
    fn new(r: Reader) -> Scanner<Reader> {
        Scanner {
            buf: vec![0; 8192],
            len: 0,
            idx: 0,
            next: None,
            reader: r,
        }
    }

    fn next<T: std::str::FromStr>(&mut self) -> T {
        self.wrapped::<T>().unwrap()
    }

    fn vec<T: std::str::FromStr>(&mut self, n: usize) -> Vec<T> {
        (0..n).map(|_| self.next()).collect()
    }

    fn mat<T: std::str::FromStr>(&mut self, r: usize, c: usize) -> Vec<Vec<T>> {
        (0..r).map(|_| self.vec(c)).collect()
    }

    fn vec_char(&mut self) -> Vec<char> {
        self.read();
        self.next.take().unwrap().chars().collect()
    }

    fn mat_char(&mut self, r: usize) -> Vec<Vec<char>> {
        (0..r).map(|_| self.vec_char()).collect()
    }

    fn wrapped<T: std::str::FromStr>(&mut self) -> Option<T> {
        self.read();
        self.next.take().and_then(|s| s.parse::<T>().ok())
    }

    fn read(&mut self) -> bool {
        if self.next.is_some() {
            return true;
        }
        let mut s = String::with_capacity(16);
        while let Some(c) = self.get_char() {
            if !c.is_whitespace() {
                s.push(c);
            } else if !s.is_empty() {
                break;
            }
        }
        self.next = if !s.is_empty() { Some(s) } else { None };
        self.next.is_some()
    }

    fn get_char(&mut self) -> Option<char> {
        if self.idx == self.len {
            match self.reader.read(&mut self.buf[..]) {
                Ok(l) if l > 0 => {
                    self.idx = 0;
                    self.len = l;
                }
                _ => return None,
            }
        }
        self.idx += 1;
        Some(self.buf[self.idx - 1] as char)
    }
}

Submission Info

Judge Result