1、定义中间变量
int a = 1,b = 2,t ;t = a;a = b;b = t;
2、求和，可不用定义中间变量
int a = 1,b = 2;a = a + b;b = a - b;a = a - b;
3、异或
int temp = p ^ q;p = temp ^ p;q = temp ^ q;
数据互换
原文：http://www.cnblogs.com/wwjdx/p/6435639.html
