1 #include <stdio.h>
 2 #include <stdlib.h>
 3 //打印数组元素
 4 void print(int arr[], int n){
 5     for(int i = 0; i < n; ++i){
 6         printf("%d ", arr[i]);
 7     }
 8     puts("");
 9 }
10 //比较函数 升序
11 int comp(const void *a, const void *b){
12     int *numa = (int *)a, *numb = (int *)b;
13     return *numa - *numb;
14 }
15 
16 int main(){
17     int a[100], n = 20;
18     
19     for(int i = 0; i < n; ++i){
20         a[i] = n - i;
21     }
22 
23     print(a, n);
24     //数组a 排序数目n个 int字节大小 按照comp函数比较
25     qsort(a, n, sizeof(int), comp);
26 
27     print(a, n);
28 
29     return 0;
30 }

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 //打印数组元素
 4 void print(int arr[], int n){
 5     for(int i = 0; i < n; ++i){
 6         printf("%d ", arr[i]);
 7     }
 8     puts("");
 9 }
10 //比较函数 降序
11 int comp(const void *a, const void *b){
12     int *numa = (int *)a, *numb = (int *)b;
13     return *numb - *numa;
14 }
15 
16 int main(){
17     int a[100], n = 20;
18     
19     for(int i = 0; i < n; ++i){
20         a[i] = i + 1;
21     }
22 
23     print(a, n);
24     //数组a 排序数目n个 int字节大小 按照comp函数比较
25     qsort(a, n, sizeof(int), comp);
26 
27     print(a, n);
28 
29     return 0;
30 }