rust quick sort

quick_sort.rs

fn main() {
    let mut list = vec![
        12, 43, 54, 324, 1, 5, 6, 23, 98, 34, 65, 32, 58, 31, 4, 673,
    ];
    let len = list.len();
    quick_sort(&mut list, 0, len);
    println!("{:?}", list);
}


fn quick_sort(list: &mut Vec<i32>, left: usize, right: usize) {
    if left < right {
        let mid = partition(list, left, right);
        quick_sort(list, left, mid - 1);
        quick_sort(list, mid + 1, right);
    }
}

fn partition(list: &mut Vec<i32>, left: usize, right: usize) -> usize {
    // 用left值为默认的pivot
    let pivot = left;
    // 位于index之前的值，都是比pivot小的
    let mut index = pivot + 1;
    for i in index..right {
        if list[i] < list[pivot] {
            // 如果i值小于pivot值，把i当前的值与index替换，然后index往后移一位
            swap(i, index, list);
            index += 1;
        }
    }
    // 遍历完成，替换pivot和index-1的位置，使得pivot前的值都比他小
    swap(pivot, index - 1, list);
    // 返回mid位置
    index - 1
}

fn swap(x: usize, y: usize, list: &mut Vec<i32>) {
    list.swap(x, y);
}