函数实现两个数的交换

#include <stdio.h>
void swap(int*p1, int*p2)
{
int tmp = *p1;
*p1 = *p2;
*p2 = tmp;
}
void main()
{
int p1 = 1;
int p2 = 2;
int *num1 = &p1;
int *num2 = &p2;
swap(num1, num2);
printf("p1=%d p2=%d\n", p1, p2);
system("pause");
}