不使用中间变量交换整型数据的值

思想就是通过简单的加减运算凑出最终的值。

代码：

#include <iostream>using namespace std;int main(){     int a = 1;     int b = 4;          cout << "before swap" << endl;     cout <<"a= " << a<< endl;     cout <<"b= " << b<< endl;          //do swap without temp     a = a - b;     b = a + b;     a = b - a;          cout << "after swap" << endl;     cout <<"a= " << a<< endl;     cout <<"b= " << b<< endl;     return 0;}