写出以下程序的运行结果：
#include<stdio.h>
void fun2(int x, int y)
{
int t;
t=x; x=y; y=t;
}
void fun1(int *x,int *y)
{
int t;
t=*x; *x=*y;*y=t;
}
void main()
{
int x,y;
x=10 ; y=20;
fun1(&x,&y);
printf("x=%d y=%d\n",x,y);
x=1; y=3;
fun2(x,y);
printf("x=%d y=%d\n",x,y);
}
