バブルソート、選択ソート、挿入ソート、マージソート

sort.rs

fn bubble_sort(values: &Vec<i32>) -> Vec<i32> {
    let mut result = values.clone();

    for i in 0..(values.len() - 2) {
        for base in 0..(values.len() - i) {
            let target_index = base + 1;
            if target_index >= values.len() {
                break;
            }

            if result[base] > result[target_index] {
                result = swap(result, base, target_index);
            }
        }
    }

    result
}

fn selection_sort(values: &Vec<i32>) -> Vec<i32> {
    let mut result = values.clone();

    for i in 0..(result.len() - 1) {
        let mut min = i;
        for j in (i + 1)..result.len() {
            if result[j] < result[min] {
                min = j;
            }
        }
        result = swap(result, i, min);
    }
    result
}

fn insertion_sort(values: &Vec<i32>) -> Vec<i32> {
    let mut result = values.clone();

    if result[0] > result[1] {
        result = swap(result, 0, 1);
    }

    for i in 1..(result.len() - 1) {
        if result[i] > result[i + 1] {
            let mut base = i + 1;
            let mut target_index = i;

            loop {
                result = swap(result, base, target_index);

                if target_index as i32 - 1 < 0 || result[base - 1] > result[target_index - 1] {
                    break;
                }

                base -= 1;
                target_index -= 1;
            }
        }
    }
    result
}

fn merge_sort(values: &Vec<i32>) -> Vec<i32> {
    values.chunks(2).fold(vec![0; 0], |mut acc, x| {
        acc.append(&mut x.to_vec());
        insertion_sort(&acc)
    })
}

fn swap(values: Vec<i32>, from: usize, to: usize) -> Vec<i32> {
    let mut result = values.clone();
    let tmp = result[from];
    result[from] = result[to];
    result[to] = tmp;

    result
}

fn display(values: &Vec<i32>) {
    println!("{:?}", values);
}

fn main() {
    let values = vec![4, 3, 100, 40, 1, 7, 5];

    println!("Bubble Sort");
    display(&values);
    let r = bubble_sort(&values);
    display(&r);
    println!("");
    println!("Selection Sort");
    display(&values);
    let r = selection_sort(&values);
    display(&r);
    println!("");
    println!("Insertion Sort");
    display(&values);
    let r = insertion_sort(&values);
    display(&r);
    println!("");
    println!("Merge Sort");
    display(&values);
    let r = merge_sort(&values);
    display(&r);
}