求c++问题！！！！！照书上抄的程序怎么编译错误？

#include<iostream>
#include<string>
using namespace std;
int main()
{
string string1,string2,string3,temp;
cout<<"please input three strings:";
cin>>string1>>string2>>string3;
if(string2>string3){temp=string2;string2=string3;string3=temp;}
if(string1<=string2)cout<<string1<<" "<<string2<<" "<<string3<<endl;
else if(string1<=string3)cout<<string2<<" "<<string1<<" "<<string3<<endl;
else cout<<string2<<" "<<string 3<<" "<<string1<<endl;
return 0;
}
//为什么这个编译错误，这是照书上抄的？

else cout<<string2<<" "<<string 3<<" "<<string1<<endl;
这一句 string3中间你多了一个空格，把它删了
希望可以帮到你