输入3个字符串，要求字母按从小到大顺序输出

#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; }elsecout<<string2<<" "<<string3<<" "<<string1<<endl;}