cin

#include <iostream>
using namespace std;

int main(int argc, char const *argv[])
{
    cout<<"请输入2个整数:";
    int a,b;
    cin>>a>>b;
    //从小到大排列
    if (a<b)
        cout << a << " " <<b<<endl;
    else
        cout << b << " " <<a<<endl;
    return 0;
}

iMac-52:array apple$ ./a.out
请输入2个整数:12 23
12 23
iMac-52:array apple$ ./a.out
请输入2个整数:23 12
12 23