清华出版社发行的教材，代码运行错误，请名位大神指导一下，谢谢
#include<stdio.h>void swap(int *p1, int *p2) /*自定义交换函数*/
{
int temp;
temp = *p1;
*p1 = *p2;
*p2 = temp;
}
void exchange(int *pt1, int *pt2, int *pt3) /*三个数由大到小排序*/
{
if (*pt1 < *pt2)
swap(pt1, pt2); /*调用swap函数*/
if (*pt1 < *pt3)
swap(pt1, pt3);
if (*pt2 < *pt3)
swap(pt2, pt3);
}
main()
{
int a, b, c, *q1, *q2, *q3;
puts("Please input three key numbers you want to rank:");
scanf("%d,%d,%d", &a, &b, &c);
q1 = &a; /*将变量a地址赋给指针变量q1*/
q2 = &b;
q3 = &c;
exchange(q1, q2, q3); /*调用exchange函数*/
printf("\n%d,%d,%d\n", a, b, c);
}
