1 #include<iostream> 2 using namespace std; 3 int main() 4 { 5     int a,b,sum=0; 6     cin>>a>>b; 7     for(int i=a;i<=b;i++) 8         sum+=i; 9     cout<<sum;10     return 0;11 }

 1 #include<iostream> 2 #include<array> 3 using namespace std; 4 int main() 5 { 6     array<long double,100>arr; 7     arr[0]=arr[1]=1l; 8     for(int i=2;i<20;i++) 9     {10         arr[i]=i*arr[i-1];11         cout<<i<<"!="<<arr[i]<<endl;12     }13     return 0;14 }

 1 #include<iostream> 2 using namespace std; 3 int main() 4 { 5     double sum=0,a; 6     cout<<"enter the number"; 7     cin>>a; 8     for(;a!=0;) 9     {10         sum+=a;11         cin>>a;12     }13     cout<<sum;14     return 0;15 }

 1 #include<iostream> 2 using namespace std; 3 const float a=100.0; 4 float daphne(int n) 5 { 6     float da; 7     da=a+a*0.1*n; 8     return da; 9 }10 11 float cleo(int n)12 {13     float cl=a*(1+0.05);14     for(int i=1;i<n;i++)15     {16         cl=cl*(1+0.05);17     }18     return cl;19 }20 21 int main()22 {23     float b,c;24     int i;25     for(i=1;;i++)26     {27         b=daphne(i);28         c=cleo(i);29         if(c>b)break;30     }31     cout<<"year="<<i<<endl;32     cout<<"dephne="<<b<<endl;33     cout<<"cleo="<<c<<endl;34     return 0;35 36 }
37 网上下载版38 #include <iostream>  39 using namespace std;  40 void main()  41 {  42     double Dsum=100;  43     double Csum=100;  44     int i=0;  45     while (Csum<=Dsum)  46     {  47         Dsum+=10;  48         Csum+=Csum*0.05;  49         i++;      50     }  51     cout<<"After "<<i<<" year, Csum is bigger than Dsum"<<endl;  52     cout<<"Dsum="<<Dsum<<"   Csum="<<Csum;  53     cin.get();  54 }

 1 #include<iostream> 2 using namespace std; 3 int main() 4 { 5     char*mon[12]={"1","2","3","4","5","6","7","8","9","10","11","12"}; 6     int num[12]; 7     int sum=0; 8     for(int i=0;i<12;i++) 9     {10         cout<<"enter the number of the No."<<mon[i]<<" monthe .";11         cin>>num[i];12         sum+=num[i];13     }14     cout<<sum;15     return 0;16 }

 1 #include<iostream> 2 using namespace std; 3 int main() 4 { 5     char*mon[3][12]={"1","2","3","4","5","6","7","8","9","10","11","12","1","2","3","4","5","6","7","8","9","10","11","12","1","2","3","4","5","6","7","8","9","10","11","12"}; 6     int num[3][12]; 7     int sum[4]={0}; 8     for(int j=0;j<3;j++) 9     {10         for(int i=0;i<12;i++)11         {12             cout<<"enter the number of the No."<<mon[j][i]<<" monthe .";13             cin>>num[j][i];14             sum[j]+=num[j][i];15         }16     }17     cout<<sum[0]<<","<<sum[1]<<","<<sum[2]<<","<<sum[0]+sum[1]+sum[2]<<","<<endl;;18     return 0;19 }

 1 #include<iostream> 2 #include<string> 3 using namespace std; 4 struct car 5 { 6     string make; 7     int year; 8 }; 9 int main()10 {11     int n;12     cout<<"how may do you wish to catalog? ";13     cin>>n;14     car*ps=new car[n];15     for(int i=0;i<n;i++)16     {17         cin.get();18         cout<<"Car #"<<i+1<<endl;19         cout<<"please enter the make: ";20         getline(cin,ps[i].make);21         cout<<"please enter the year made: ";22         cin>>ps[i].year;23     }24     cout<<"here is your collection"<<endl;25     for(int i=0;i<n;i++)26     {27         cout<<ps[i].year<<" "<<ps[i].make<<endl;28     }29     return 0;30 }

 1 #include<iostream> 2 #include<cstring> 3 using namespace std; 4 int main() 5 { 6     char word[20]; 7     int i=0; 8     cout<<"enter words(to stop, type the word done):"<<endl; 9     cin>>word;10     while(strcmp(word,"done")!=0)11     {12         i++;13         cin>>word;14     }15     cout<<"you entered a total of "<<i<<" words."<<endl;16     return 0;17 }

 1 #include<iostream> 2 #include<string> 3 using namespace std; 4 int main() 5 { 6     string word; 7     cout<<"enter words(to stop, type the word done):"<<endl; 8     cin>>word; 9     int count=0;10     for(;word!="done";)11     {12         count++;13         cin>>word;14     }15     cout<<"you entered a total of "<<count<<" words."<<endl;16     return 0;17 }

 1 #include<iostream> 2 using   namespace std; 3 int main() 4 { 5     int i; 6     cout<<"enter number of rows "; 7     cin>>i; 8     for(int j=0;j<i;j++) 9     {10         int k=4-j,m=j+1;11         for(int n=0;n<k;n++)12         {cout<<".";}13         for(int n=0;n<m;n++)14         {cout<<"*";}15         cout<<endl;16     }17     return 0;18 }