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 ;
}

2-29 while

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

do…while

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

for

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

2-32 while

#include <iostream>
using namespace std;
int main()
{ int n=,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 ;
 }

do…while

#include <iostream>
using namespace std;
int main()
{ int n=,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 ;
 }

2-34

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

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。