00003 不用第三片空间实现两个数的交换

public class T {
public static void main(String []args){
int a=1,b=2;
swap1(a, b);
swap2(a, b);

}
public static void swap1(int a,int b){
a=a+b;
b=a-b;
a=a-b;
System.out.println("a="+a+"  b="+b);
}
public static void swap2(int a,int b){
a=a^b;
b=a^b;
a=a^b;
System.out.println("a="+a+"  b="+b);
}
}