#include <iostream>
using namespace std;
int main()
{
int code_enter;
const int code=8888;

cout<"Enter your pass code."<<endl;
cin>>code_enter;

if(code_enter!=code)
{
cout<<"your are wrong.Enter it again."<<endl;
cin>>code_enter;
}

if(code_enter==code)
{
cout<"Access approved."<<endl;
cout<<"welcome"<<endl;
}
else
cout<<"Access denied."<<endl;
return 0;
}

#include <iostream>
using namespace std;
int main()
{
int code_enter;
const int code=8888;

cout<"Enter your pass code."<<endl;
cin>>code_enter;

if(code_enter!=code)
{
cout<<"your are wrong.Enter it again."<<endl;
cin>>code_enter;
}

if(code_enter==code)
{
cout<"Access approved."<<endl;
cout<<"welcome"<<endl;
}
else
cout<<"Access denied."<<endl;
return 0;
}
红颜色处，少了一个符号！
改为：
cout<<"Enter your pass code."<<endl;
cout<<"Access approved."<<endl;

楼上那位朋友，你是重庆大学的？
我是重庆万州的人