C 语言 用指针的方式比较三个数的大小，并从大到小输出

#include<stdio.h>
void num1(){
    int a,b,c;
	int d;
	printf("输入要比较的数：\n");
	scanf("%d %d %d",&a,&b,&c);
	int *p1,*p2,*p3;
	p1 =&a;
	p2 =&b;
	p3 =&c;
	if (a<b){
		d = a;
	    a = b;
	    b = d;
	}
	if (a<c){
	   d = a;
	   a = c;
	   c = d;
	}
	if (b<c){
	   d = b;
	   b = c;
	   c = d;
	}
	printf("排序后的数为：\n");
	printf("%d %d %d \n",a,b,c);
}

int main(){
	num1();
	return 0;
}