题解

#include<iostream>
#include<cstring>
using namespace std;
int main(){
    string a,b,c;
    cin>>a;
    for(short i=0;i<a.size();i++){
        if(i%2==0) b+=a[i];
        else c+=a[i];
    }
    if(b>c){
		cout<<b<<c;
	 } 
	else {
		cout<<c<<b;
	}
	return 0;
}

……

#include<iostream>
#include<cstring>
using namespace std;
void Iamgood(){
    string a,b,c;
    cin>>a;
    for(short i=0;i<a.size();i++){
        if(i%2==0) b+=a[i];
        else c+=a[i];
    }
    if(b>c){
		cout<<b<<c;
	 } 
	else {
		cout<<c<<b;
	}
}
int main(){
    Iamgood();
}