引用，比较两数大小。8

#include<iostream>
using namespace std;
int max(int &x,int &y)
{
if(x<y)
x=y;
return x;
}
int main()
{
int a,b;
cin>>a>>b;
cout<<"max(a,b)="<<max(a,b)<<endl;
return 0;

}