C＋＋实验一

实验结论

2-28 if...else

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

}

 

switch

#include <iostream>
using namespace std;
int main()
{ char c;
while (true) 
{cout<<"Menu: A(dd) D(elect) S(ort) Q(uit) Select one: ";cin>>c;
switch(c) 
{ case 'A':cout<<"数据已经增加"<<endl;continue;
case 'D':cout<<"数据已经减少"<<endl;continue;
case 'S':cout<<"数据已经排序"<<endl;continue;
case 'Q':break;
}
break;
}
return 0;
}

 

 

2-29 while

#include <iostream>
#include <cmath>
using namespace std;
int main()
 { int n=2,i,f,t=0;
   while(n<=100)    
    {f=0;
     for(i=2;i<=sqrt(n);i++)
       if(n%i==0)
        {f=1;
         break;
        }
     if(f==0)
       {cout<<"  "<<n;
        t++;
        if(t%5==0)
         cout<<endl;
       }
     n++;
  }
}

 

 do...while

#include <iostream>
#include <cmath>
using namespace std;
int main()
 { int n=2,i,f,t=0;
   do    
    {f=0;
     for(i=2;i<=sqrt(n);i++)
       if(n%i==0)
        {f=1;
         break;
        }
     if(f==0)
       {cout<<"  "<<n;
        t++;
        if(t%5==0)
         cout<<endl;
       }
     n++; 
  }while(n<=100);
}

 for

#include <iostream>
#include <cmath>
using namespace std;
int main()
 { int n=2,i,f,t=0;
   for(;n<=100;)   
    {f=0;
     for(i=2;i<=sqrt(n);i++)
       if(n%i==0)
        {f=1;
         break;
        }
     if(f==0)
       {cout<<"  "<<n;
        t++;
        if(t%5==0)
         cout<<endl;
       }
     n++;
  }
}

2-32 while

#include <iostream>
using namespace std;
int main()
{ int n=70,m;
  cout<<"please guess the nunmber(1-100): ";cin>>m;
  while(n!=m)
    {if(m<n)
      {cout<<"bigger than the number: ";cin>>m;}
     else 
      {cout<<"smaller than the number: ";cin>>m;}
    }
  cout<<"You are right!"<<endl;
  return 0;
 }

 do...while

#include <iostream>
using namespace std;
int main()
{ int n=70,m;
  cout<<"please guess the nunmber(1-100): ";cin>>m;
  do
    {if(m<n)
      {cout<<"bigger than the number: ";cin>>m;}
     else 
      {cout<<"smaller than the number: ";cin>>m;}
    }while(n!=m);
  cout<<"You are right!"<<endl;
  return 0;
 }

2-34

#include <iostream>
using namespace std;
int main()
{ int i,j,k,r=0;
  int c1,c2,c3;
  cout<<"Red: 0,Yellow: 1,Blue: 2,White: 3,Black:4"<<endl; 
  int a[5]={0,1,2,3,4};
  for(i=0;i<=4;i++)
    {c1=a[i];
     for(j=i+1;j<=4;j++)
       {c2=a[j];
        for(k=j+1;k<=4;k++)
          {c3=a[k];
           r++;
           cout<<c1<<c2<<c3<<endl;}
        c2=a[j]; 
       } 
      c1=a[i];
     }
  cout<<"取法有："<<r<<"种"<<endl;
  return 0;
}

实验总结与体会

格式与C语言有点区别，还是要学挺多东西的。穷举法不会。