int a = 2; int b = 7; a = a + b; b = a - b; // b = a + b - b = a a = a - b; // a + b - a = b -------------------------------------------------------- int a = 2; int b = 7; a = a ^ b; b = a ^ b; a = a ^ b;
原文：https://www.cnblogs.com/blog-ice/p/15242204.html