#include <iostream>
using namespace std;
void jiaohuan(int &x, int &y);
int main()
{
int a,b;
cin>>a>>b;
if (a<b) jiaohuan(a, b);
cout<<"a,b="<<a<<","<<b;
return 0;
}
void jiaohuan(int &x, int &y)
{
int t;
t=x;
x=y;
y=t;
}
心得体会:形参为引用量,x是a的别称, 是b的别称,此处改变x,y 实际改变了a,b