实验一

2-28 while

#include <iostream>
using namespace std;
int main () 
{  	
    while(true)
   { char n;
 
		 cout<<"Menu : A (dd) D (elete) S (ort) Q (uit), Select one :"<<endl;
	     cin>>n;
      if(n=='A')  
	    {cout<<"data has been added"<<endl;
	     continue;
	    }
	     else if(n=='D')
	          {cout<<"data has been deleted"<<endl;
	           continue;
	          }
		    else if(n=='S')
			{cout<<"data has been sorted"<<endl;
			 continue;
		    }
		         
			   else if (n=='Q')
			        break;
				  else
				    cout<<"please input another number"<<endl; 
	 }
				    return 0;
		       
}

　　

2-28 DO WHILE

#include <iostream>
using namespace std;
int main()
{ while(true)
    { char n;
         cout<<"Menu : A (dd) D (elete) S (ort) Q (uit), Select one :"<<endl;
	     cin>>n;
	     switch(n)
	     { case'A' : cout<<"data has been added"<<endl;
	                 continue;
	       case'D' : cout<<"data has been deleted"<<endl;
	                 continue;
	       case'S' : cout<<"data has been sorted"<<endl;
			         continue;
		   case'Q' : break;
		   default : cout<<"please input another number"<<endl;
	      }  
	 }return 0;
}

　　

2-29 while

#include <iostream>
using namespace std;
int main()
{ int i=2,j,n,f;
   while(i<=100)
   {f=1;
    n=i/2;
    j=2;
    while(j<=n)
     {if (i%j==0)
        {f=0;
         break;
        }
        j++;
     }
     if(f==1)
     cout<<i<<endl;
     i++;
   }
   return 0;
}

　

2-29 do while

#include <iostream>
#include <cmath>
using namespace std;
int main()
{ int i=2,j,n,m;
   do
   {m=1;
    n=i/2;
    j=2;
    while(j<=n)
     {if (i%j==0)
        {m=0;
         break;
        }
        j++;
     }
     if(m)
     cout<<i<<endl;
     i++;
   }while(i<=100);
   return 0;
}

　　

2-29 for

#include <iostream>
using namespace std;
int main()
{ int i,j,f,n;
  for(i=2;i<=100;i++)
    {f=1;
     n=i/2;
     for(j=2;j<=n;j++)
     {if(i%j==0)
        {f=0;
         break;}
	 }
	  if(f==1)
	  cout<<i<<endl;
	}
	return 0;
 } 

　

2-32 while

#include <iostream>
using namespace std;
int main()
 { int a=62,b;
    cout<<"Please input a number:"<<endl;
    cin>>b;
    while(a>b)
    {cout<<"smaller than the number"<<endl;
     cin>>b;
	}
	while(a<b)
	{cout<<"bigger than the number"<<endl;
	 cin>>b;
	}while(a==b)
	 {
	 cout<<"Congratulations!You got it!"<<endl;
	 break;}
	 return 0;
  } 

　　

2-32 do while

#include <iostream>
using namespace std;
int main()
 { int a=62,b;
    cout<<"Please input a number:"<<endl;
    cin>>b;
    do 
    {cout<<"smaller than the number"<<endl;
     cin>>b;
	}while(a>b);
	do
	{cout<<"bigger than the number"<<endl;
	 cin>>b;
	}while(a<b);
	 do
	 {cout<<"Congratulations!You got it!"<<endl;
	  break;
	 }while(a==b);
	 return 0;
  } 

　　

2-34 

#include <iostream>
using namespace std;
int main()
  {
	int i,j,k,n=0;
	for(i=1;i<=5;i++)
	{for(j=i;j<=5;j++)
	   if(i!=j)
	   {for(k=j+1;k<=5;k++)
	     if(k!=i&&k!=j){
		   n++;
	       cout<<i<<"  "<<j<<"  "<<k<<endl;}
	   }
	}
	cout<<n<<endl;
	return 0;
}