main.rs

fn main() {
    println!("\n*** Chapter 05 ***\n");

    let mut v = vec![4, 2, 7, 1, 3];
    println!("Vector: {:?}", v);
    selection_sort(&mut v);
    println!("Sorted: {:?}\n", v);

    let mut v = vec![5, 4, 3, 2, 1];
    println!("Vector: {:?}", v);
    selection_sort_extra(&mut v);
    println!("Sorted: {:?}\n", v);
}

fn selection_sort(data: &mut [i32]) {
    let data_len = data.len();
    if data_len < 2 {
        return;
    }
    for i in 0..(data_len - 1) {
        let mut min = i;
        for j in (i + 1)..data_len {
            if data[j] < data[min] {
                min = j;
            }
        }
        if i != min {
            data.swap(i, min);
        }
        println!("Sorted index {i}: {:?}", data);
    }
}

//// Rust Extras
fn selection_sort_extra(data: &mut [i32]) {
    let data_len = data.len();
    if data_len < 2 {
        return;
    }
    for i in 0..(data_len - 1) {
        let min = (i..data_len).min_by_key(|x| data[*x]).unwrap();
        data.swap(i, min);
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_selection_sort() {
        let mut v: Vec<i32> = vec![];
        selection_sort(&mut v);
        assert_eq!(v, Vec::<i32>::new());

        let mut a = [65, -55, 45, -35, 0, 15, 10];
        selection_sort(&mut a);
        assert_eq!(a, [-55, -35, 0, 10, 15, 45, 65]);
    }

    #[test]
    fn test_selection_sort_extra() {
        let mut v: Vec<i32> = vec![];
        selection_sort_extra(&mut v);
        assert_eq!(v, Vec::<i32>::new());

        let mut a = [65, -55, 45, -35, 0, 15, 10];
        selection_sort_extra(&mut a);
        assert_eq!(a, [-55, -35, 0, 10, 15, 45, 65]);
    }
}