关于c:冒泡排序

#include <stdio.h>
#include <stdlib.h>

void display(int* arr, int length)
{
    for (int i = 0; i < length; ++i)
    {
        printf("%d%s", arr[i], i == length - 1 ? " " : ", ");
    }

    printf("\n");
}

void swap(int* a, int* b)
{
    int temp = *a;
    *a = *b;
    *b = temp; 
}

void bubble(int* arr, int length)
{
    for (int i = 0; i < length - 1; ++i)
    {
        for (int j = 0; j < length - 1 - i; ++j)
        {
            if (arr[j] > arr[j + 1]) {
                swap(&arr[j], &arr[j + 1]);
            }
        }
    }
}

int main(int argc, char const *argv[])
{
    int arr[] = {2, 3, 5, 21, 2, 3, 999, 2, 34, 87};

    int length = sizeof(arr) / sizeof(int);

    display(arr, length);

    bubble(arr, length);

    display(arr, length);

    return 0;
}