下列程序的輸出結(jié)果是（）.
main()
{ int x=1,y=0,a=0,b=0;
switch(x)
{
case 1:switch(y)
{
case 0:a++;break;
case 1:b++;break;
}
case 2:a++;b++;break;
case 3:a++;b++;break;
}
printf("a=%d,b=%d\n",a,b);
}