用C语言用指针函数排序

可以使用指针函数来排序，具体实现方法可以参考以下代码：

#include <stdio.h>

void sort(int *arr, int n, int (*compare)(int, int)) {
    int i, j, temp;
    for (i = ; i < n - 1; i++) {
        for (j = i + 1; j < n; j++) {
            if (compare(arr[i], arr[j]) > ) {
                temp = arr[i];
                arr[i] = arr[j];
                arr[j] = temp;
            }
        }
    }
}

int ascending(int a, int b) {
    return a - b;
}

int descending(int a, int b) {
    return b - a;
}

int main() {
    int arr[] = {5, 3, 8, 1, 2};
    int n = sizeof(arr) / sizeof(arr[]);
    int i;

    printf("Original array: ");
    for (i = ; i < n; i++) {
        printf("%d ", arr[i]);
    }

    sort(arr, n, ascending);
    printf("\nArray sorted in ascending order: ");
    for (i = ; i < n; i++) {
        printf("%d ", arr[i]);
    }

    sort(arr, n, descending);
    printf("\nArray sorted in descending order: ");
    for (i = ; i < n; i++) {
        printf("%d ", arr[i]);
    }

    return ;
}