1[分析题]
 

给出下面程序的输出结果

#include<iostream>

  using namespace std;

  void main()

  {

  int num=300;

  int &ref=num;

  cout<<ref;

  ref=ref-100;

  cout<<" "<<num;

  num=num-50;

  cout<<" "<<ref<<endl;

  }