Решение задачи №61 от Unilecs

calculate_cleanup_time.rs

const SPEED_REGULAR_KMPH: i64 = 50;
const SPEED_CLEANUP_KMPH: i64 = 20;

type Point = (i64, i64);

struct Segment {
    start: Point,
    end:   Point,
}

fn sqr (x: i64) -> i64 {
    x * x
}

impl Segment {
    fn hypot (&self) -> i64 {
        let &Segment {start: (x1, y1), end: (x2, y2)} = self;
        sqr(x1-x2) + sqr(y1-y2)
    }
    fn len (&self) -> f64 {
        (self.hypot() as f64).sqrt()
    }
}

fn calculate_cleanup_time (_: (i64, i64), segs: &[Segment]) -> f64 {
    let total: f64 = segs.iter()
        .map(|seg| seg.len() * 2.0)
        .sum();
    total / 1000.0 / SPEED_CLEANUP_KMPH as f64 * 60.0
}

fn main() {
    let path = [ 
        Segment { start: (0, 0),         end: (10000, 10000) },
        Segment { start: (5000, -10000), end: (5000,  10000) },
        Segment { start: (5000, 10000),  end: (10000, 10000) }
    ];
    let start = (0, 0);
    let answer = calculate_cleanup_time(start, &path).round() as u64;
    assert_eq!(answer, 235)
}

Ссылка на playground: https://play.rust-lang.org/?gist=28da39035581ef6a5511775dd8589e3b&version=stable

Во второй ревизии убрано ненужное копирование