#include<iostream>using namespace std;int main(){    int a=50;    int n;    while(1)//关键，造成一个死循环    {        cout<<"please input an number: "<<endl;        cin>>n;        if(a==n)//循环退出条件        {            cout<<"n="<<n<<endl;            break;        }else if(a<n)        {            cout<<"your number are biger than the number,please try again."<<endl;        }else if(a>n)        {            cout<<"your number are smaller than the number,please try again."<<endl;        }    }    return 0;}