Submission #2012449

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Source Code Expand

#[allow(unused_imports)]
use std::cmp::{max, min, Ordering};
#[allow(unused_imports)]
use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, VecDeque};
#[allow(unused_imports)]
use std::iter::FromIterator;
#[allow(unused_imports)]
use std::io::{stdin, stdout, BufWriter, Write};
mod util {
    use std::io::stdin;
    use std::str::FromStr;
    use std::fmt::Debug;
    #[allow(dead_code)]
    pub fn line() -> String {
        let mut line: String = String::new();
        stdin().read_line(&mut line).unwrap();
        line.trim().to_string()
    }
    #[allow(dead_code)]
    pub fn gets<T: FromStr>() -> Vec<T>
    where
        <T as FromStr>::Err: Debug,
    {
        let mut line: String = String::new();
        stdin().read_line(&mut line).unwrap();
        line.split_whitespace()
            .map(|t| t.parse().unwrap())
            .collect()
    }
}
#[allow(unused_macros)]
macro_rules ! get { ( $ t : ty ) => { { let mut line : String = String :: new ( ) ; stdin ( ) . read_line ( & mut line ) . unwrap ( ) ; line . trim ( ) . parse ::<$ t > ( ) . unwrap ( ) } } ; ( $ ( $ t : ty ) ,* ) => { { let mut line : String = String :: new ( ) ; stdin ( ) . read_line ( & mut line ) . unwrap ( ) ; let mut iter = line . split_whitespace ( ) ; ( $ ( iter . next ( ) . unwrap ( ) . parse ::<$ t > ( ) . unwrap ( ) , ) * ) } } ; ( $ t : ty ; $ n : expr ) => { ( 0 ..$ n ) . map ( | _ | get ! ( $ t ) ) . collect ::< Vec < _ >> ( ) } ; ( $ ( $ t : ty ) ,*; $ n : expr ) => { ( 0 ..$ n ) . map ( | _ | get ! ( $ ( $ t ) ,* ) ) . collect ::< Vec < _ >> ( ) } ; ( $ t : ty ;; ) => { { let mut line : String = String :: new ( ) ; stdin ( ) . read_line ( & mut line ) . unwrap ( ) ; line . split_whitespace ( ) . map ( | t | t . parse ::<$ t > ( ) . unwrap ( ) ) . collect ::< Vec < _ >> ( ) } } ; }
#[allow(unused_macros)]
macro_rules ! debug { ( $ ( $ a : expr ) ,* ) => { println ! ( concat ! ( $ ( stringify ! ( $ a ) , " = {:?}, " ) ,* ) , $ ( $ a ) ,* ) ; } }

fn dist((x1, y1): (f64, f64), (x2, y2): (f64, f64)) -> f64 {
    f64::sqrt((x1 - x2).powi(2) + (y1 - y2).powi(2))
}

fn angle((x1, y1): (f64, f64), (x2, y2): (f64, f64), (x3, y3): (f64, f64)) -> f64 {
    let (vx1, vy1) = (x1 - x2, y1 - y2);
    let (vx2, vy2) = (x3 - x2, y3 - y2);

    f64::acos(
        (vx1 * vx2 + vy1 * vy2).abs()
            / (f64::sqrt(vx1 * vx1 + vy1 * vy1) * f64::sqrt(vx2 * vx2 + vy2 * vy2)),
    )
}

fn check(r: f64, l1: f64, l2: f64, l3: f64, a1: f64, a2: f64) -> bool {
    let x = r / f64::sin(a1 / 2.0) * f64::cos(a1 / 2.0);
    let y = r / f64::sin(a2 / 2.0) * f64::cos(a2 / 2.0);

    l1 >= 2.0 * r + x + y && l2 >= x && l3 >= y
}

fn main() {
    let a = get!(f64, f64);
    let b = get!(f64, f64);
    let c = get!(f64, f64);

    let mut l = 0.0;
    let mut r = 1000.0;

    for _ in 0..1000 {
        let mid = (l + r) / 2.0;

        if check(
            mid,
            dist(a, b),
            dist(a, c),
            dist(b, c),
            angle(c, a, b),
            angle(a, b, c),
        )
            || check(
                mid,
                dist(a, c),
                dist(b, c),
                dist(a, b),
                angle(a, c, b),
                angle(b, a, c),
            )
            || check(
                mid,
                dist(b, c),
                dist(a, b),
                dist(a, c),
                angle(c, b, a),
                angle(a, c, b),
            ) {
            l = mid;
        } else {
            r = mid;
        }
    }

    println!("{}", (l + r) / 2.0);
}

Submission Info

Judge Result