交换两个整形数a和b

转载自http://user.qzone.qq.com/306741422/blog/1271536177

菜鸟版:

int temp = a;

            a = b;

            b = temp;

入门版:

           a = a + b;

           b = a -  b;

           a = a - b;

高手版:

          a  = a ^ b;

          b =  a ^ b;

          a  = a ^ b;

专家版:

         a = b + 0 * (b = a);