实验1

 2-28

using namespace std;
int main()
{
    char n;
    cout<<"Menu: A(dd) D(elete) S(ort) Q(uit),Select one: "<<endl;
    cin>>n;
    while(n!='Q')
    {
        switch(n)
           {
            case 'A':
            {
                cout<<"数据已经增加"<<endl;break;
            }
            case 'D':
            {
                 cout<<"数据已经删除"<<endl;break;
            }
            case 'S':
            {
                cout<<"数据已经排序"<<endl;break;
            }
        }
        cin>>n; 
    }
    return 0;
}

 

 

#include <iostream>
using namespace std;
int main()
{
    char n;
    cout<<"Menu: A(dd) D(elete) S(ort) Q(uit),Select one: "<<endl;
  do{
      cin>>n;    
      if(n=='A'){cout<<"数据已经增加!"<<endl;continue;}
      if(n=='D'){cout<<"数据已经删除!"<<endl;continue;}
      if(n=='S'){cout<<"数据已经排序!"<<endl;continue;}
      else break;
}while(n!='Q');
    return 0;
}

2-29

 

#include <iostream>
using namespace std;
int main() 
{
    int j,i,m,n;
    i=2;
    while(i<101)
    {m=1;n=i/2;j=2;
        while(j<=n)
        {
            if(i%j==0)
            {m=0;break;}
            j++;
        }
        if(m)
            cout<<i<<"  ";
        i++;
        }
    return 0;
}

#include <iostream>
using namespace std;
int main() 
{
    int j,i,m,n;
    i=2;
   do 
   {m=1;n=i/2;j=2;
        while(j<=n)
        {
            if(i%j==0)
            {m=0;break;}
            j++;
        }
        if(m)
            cout<<i<<"  ";
        i++;
        }while(i<101); 
    return 0;
}

#include <iostream>
int main() {
    int j,i,m,n;
    i=2;
    for(;i<101;i++)
    {m=1;n=i/2;j=2;
        for(;j<=n;j++)
        {
            if(i%j==0)
            {m=0;break;}
            j++;
        }
        if(m)
            std::cout<<i<<"  ";
    }
    return 0;
}

#include <iostream>
#include <stdlib.h>
#include <time.h>
using namespace std;
int main()
{
int x;
srand(time(0));
int number=rand()%100+1;
cout<<"猜一下这个数: ";
cin>>x;
while(1)
{
if(x!=number)
{ if(x>number)
{cout<<"比这个数字大"<<endl;}
else
{cout<<"比这个数字小"<<endl;}
}
else
{cout<<"正确"<<endl;break;}
cin>>x;
}
return 0;
}

#include <iostream>
#include <stdlib.h>
#include <time.h>
using namespace std;
int main()
{
int x;
srand(time(0));
int number=rand()%100+1;
cout<<"猜一下这个数: ";
cin>>x;
do
{
if(x!=number)
{ if(x>number)
{cout<<"比这个数字大"<<endl;}
else
{cout<<"比这个数字小"<<endl;}
}
else
{cout<<"正确"<<endl;break;}
cin>>x;
}while(1);
return 0;
}

2-34

#include<iostream>
using namespace std;
int js(int);
int main()
{
    int  i, n,m;
    cin>>n;
    i=3;
    m=js(n)/(js(i)*js(n-i));
    cout<<m<<endl;
    return 0;
}
int js(int m)
{
    int x=1,y;
    for (y=1; y<=m;y++)
        {
          x=x*y;
        }
        return x;
}