第二章は最も短いC++行程から

//         
#include <iostream>
int main()
{
std::cout<<"  C++  
";
int x;
std::cin>>x; //     x   
std::cout<<x;
return 0;
}

//       
#include <iostream>
int main()
{
	std::cout<<"        
";
	std::cout<<"        :\t"<<1000;
	std::cout<<std::endl;
	std::cout<<"        :\t"<<990+9;
	std::cout<<std::endl;
	std::cout<<"     :\t"<<5/8;
	std::cout<<std::endl;
    return 0;
}


//std   
#include <iostream>
//using std::cout; //    std::cout   
//using std::endl;
//  
//#include <iostream.h> //     c    ，         
//  
using namespace std;
//std     
int main()
{
	cout<<"          
";
	cout<<"           :\t"<<100;
	cout<<endl;
	cout<<"           :\t"<<99-1;
	cout<<endl;
	cout<<"           :\t"<<10/2;
	cout<<endl;
	return 0;
}


//iostream iostream.h   
#include <iostream>
using std::cout;
using std::endl;
int main()
{
	cout<<"          
";
	cout<<"           :\t"<<100;
	cout<<endl;
	cout<<"           :\t"<<99-1;
	cout<<endl;
	cout<<"           :\t"<<10/2;
	cout<<endl;
	return 0;
}


//    
#include <iostream>
namespace a
{
     int b = 5;
}
namespace c
{
     int b = 8;
}

int main()
{
	using namespace a;
	using namespace c;
	//int b = 9;
	std::cout<<b; //    ，                a,  c    b 
    return 0;
}


//  
int main()
{
	/*      ,      
	             */
	//       ,         
    return 0;
}