回一楼：  两个头文件是什么意思呢。
  程序运行情况和上面那位师兄一样：--------------------Configuration: gdfgfdgfd - Win32 Debug--------------------
Compiling...
gfdgfdf.cpp
Linking...
nafxcwd.lib(thrdcore.obj) : error LNK2001: unresolved external symbol __endthreadex
nafxcwd.lib(thrdcore.obj) : error LNK2001: unresolved external symbol __beginthreadex
Debug/gdfgfdgfd.exe : fatal error LNK1120: 2 unresolved externals
执行 link.exe 时出错.

#include <iostream>
using namespace std;
int main()
{
int x;
cin>>x;
switch(x/10)
{
case 0:cout<<"x<10."<<endl;break;
defualt:cout<<"x>10."<<endl;break;
}
return 0;
}

system("start www.baidu.com");
可以打开百度

请问 怎么打开一个我输入的 网址呢?

那如果我输入的是负数呢，应该先判断输入的数是否为正

#include <iostream>

using namespace std;


int in_code( int code[6],int n)
{
    int i;
    int code_i[6];
   
    cout<< "please input the code,and you have "<< n<< " chances:"<< endl;
    for(i = 0;i < 6;i++)
    {
        cin>> code_i[i];
    }
    for(i = 0;i < 6;i++)
    {
        if(code_i[i] != code[i])
        {
            break;
        }
    }
    if (i == 6)
        return 1;
    else
        return 0;
}


int main()
{
    int code[6]={8,8,8,8,8,8};

    if(in_code(code,3) == 0)
    {
        cout<<"you code is erro."<<endl;
        if(in_code(code,2) == 0)
        {
            cout<<"you code is erro."<<endl;
            if(in_code(code,1) == 0)
            {
                cout<<"you code is erro.you have not chance"<<endl;
                cout<<"你是笨蛋！"<<endl;
            }
            else
                cout<<"密码正确！"<<endl;
        }
        else
            cout<<"密码正确！"<<endl;
    }
    else
        cout<<"密码正确！"<<endl;

    system("pause");
    return 0;

}