1: #include <stdio.h>
 2:
 3: void swap(int *a, int *b) {
 4:     int temp  = *a;
 5:     *a = *b;
 6:     *b = temp;
 7: }
 8: void sort3(int *x, int *y, int *z) {
 9:     if (*x > *y) swap(&x, &y);
10:     if (*y > *z) swap(&y, &z);
11:     if (*x > *y) swap(&x, &y);
12: }
13: int main(void) {
14:     int p, q, r;
15:     p = 4; q = 2; r = 3;
16:     printf("p=%d, q=%d, r=%d\n", p, q, r);
17:     sort3(&p, &q, &r);
18:     printf("p=%d, q=%d, r=%d\n", p, q, r);    
19:     return 0;
20: }