交换两个变量值得方法总结了一下
使用中间变量
int n1=11, n2=10;
int tmp = n1;
n1 = n2;
n2 = tmp;
Printf("n1=%d,n2=%d", n1, n2);
return 0;
加减法
int n1 = 11, n2 = 10;
n1 = n1 + n2;
n2=n1-n2;
n1 = n1 - n2;
Printf("n1=%d,n2=%d", n1, n2);
return 0;
堆栈
int n1 = 11, n2 = 10;
n2 = n1 + (n1 = n2) * 0;
Printf("n1=%d,n2=%d", n1, n2);
return 0;
一个值经过同一个数的两次异或后值不变
int n1 = 11, n2 = 10;
n1 = n1 ^ n2;
n2 = n2 ^ n1;
n1 = n1 ^ n2;
printf("n1=%d,n2=%d", n1, n2);
return 0;
原文：http://www.cnblogs.com/liubeimeng/p/4246542.html