LZ写的其实不是C++......那是纯C代码.....
我改成用C++的版本:

#include <iostream>
using namespace std;

int main()
{
    int x, y;
    cout<<"Input your age: "<<endl;
    cin>>x;
    cout<<"Input your brother's age: "<<endl;
    cin>>y;
    if (x<y)
    {
        cout<<"Your age is "<<x<<", your brother's age is "<<y<<"."<<endl;
        cout<<"Your brother is older than you!"<<endl;
    }
    else if (x>y)
    {
        cout<<"You are older than your brother!"<<endl;
    }
    else
    {
        cout<<"Both guys have the same age!"<<endl;
    }
    cout<<"Goodbye!"<<endl;
    return 0;
}