字符串运算

/*Copyright (c) 烟台大学计算机与控制工程学院Author：刘慧艳Created：Edition：V1.0Describe：字符串运算*/#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<<" "<<string3<<" "<<string1<<endl;}