pub mod scanner { pub struct Scanner { buf: Vec, } impl Scanner { pub fn new() -> Self { Self { buf: vec![] } } pub fn new_from(source: &str) -> Self { let source = String::from(source); let buf = Self::split(source); Self { buf } } pub fn next(&mut self) -> T { loop { if let Some(x) = self.buf.pop() { return x.parse().ok().expect(""); } let mut source = String::new(); std::io::stdin().read_line(&mut source).expect(""); self.buf = Self::split(source); } } fn split(source: String) -> Vec { source .split_whitespace() .rev() .map(String::from) .collect::>() } } } use std::f64::consts::PI; use crate::scanner::Scanner; fn main() { let mut scanner = Scanner::new(); let t: usize = 1; for _ in 0..t { solve(&mut scanner); } } fn f(r: f64, t: f64) -> f64 { let a = r * r * t * 0.5; let b = r * r * t.sin() * 0.5; a - b } fn solve(scanner: &mut Scanner) { let r: usize = scanner.next(); let k: usize = scanner.next(); let r = r as f64; let s = PI * r * r; let u = s / (k + 1) as f64; for i in (1..=k).rev() { let mut ng = 0.0; let mut ok = PI * 2.0; for _ in 0..100 { let t = (ok + ng) / 2.0; if f(r, t) >= u * i as f64 { ok = t; } else { ng = t; } } let l = r * (ok / 2.0).cos(); println!("{:.13}", l); } }