直接调用swap函数按大小排序即可
#include <iostream>
#include <algorithm>
using namespace std;
int main()
{
int a=0,b=0,c=0;
cin>>a>>b>>c;
int a1,b1,c1;
a1=a;b1=b;c1=c;
if(a>b)
swap(a,b);
if(a>c)
swap(a,c);
if(b>c)
swap(b,c);
cout<<a<<endl;
cout<<b<<endl;
cout<<c<<endl;
cout<<" "<<endl;
cout<<a1<<endl;
cout<<b1<<endl;
cout<<c1<<endl;
return 0;
}