第一种
int a = 1,b= 2;
int temp= a;
a = b;
b= temp;

第二种
int a = 1,b = 2;
a = a^b;
b = a^b;
a = a^b;

第三种
int a = 1,b = 2;
a = a+b;
b = a-b;
a = (a+b)-b

很不错  希望多多的分享