（test1.c）
#include <stdio.h>
void func1(int *arr, int n, int *max_num, int *min_num) {
if (n == 0) return;
*min_num = *max_num = arr[0];
if (n == 1) return;
for (int i = 0; i < n; i++) {
if (arr[i] > *max_num) *max_num = arr[i];
if (arr[i] < *min_num) *min_num = arr[i];
}
}
int main() {
int arr[] = {1,2,3,4,5};
int min_num, max_num;
func1(arr, 5, &max_num, &min_num);
printf("min=%d, max=%d\n", min_num, max_num);
return 0;
}
（Makefile）
test1.out: test1.c
gcc test1.c -o test1.out