C 语言指针理解

#include<stdio.h>

int main()
  {
    int *p1,*p2,*p,a,b;
    printf("please enter two integer numbers");
    scanf("%d,%d",&a,&b);

    p1=&a;
    p2=&b;
    if (a<b)
        {
          p=p1;
          p1=p2;
          p2=p;
         }
    printf("a=%d,b=%d\n",a,b);
    printf("max=%d,min=%d\n",*p1,*p2);
    return 0;
   }

luogan@luogan-Lenovo-G470:~/lg/temp/c数据结构与算法$ gcc ping.c 
luogan@luogan-Lenovo-G470:~/lg/temp/c数据结构与算法$ ./a.out 
please enter two integer numbers3,5
a=3,b=5
max=5,min=3