int Sum()
{
int sum=0;
for(int i=2;i<=100;i+=2)
sum+=i;
return sum;
}
void pri()
{
for(int i=1;i<=20;i++)
{
cout<<i<<' ';
if(i%5==0)
cout<<endl;
}
}

switch(Snote/10)
{
case 10: cout<<"A";break;
case 9: cout<<"A";break;
case 8:cout<<"B";break;
case 7:cout<<"C";break;
case 6:cout<<"D";break;
default:cout<<"E";break;
}

# include "iostream.h"
sum()
{int k=0,i;
for(i=1;i<=100;i++)
{if(i%2==0)
k+=i;
};
return(k);
}
void show()
{int i;
for(i=1;i<=20;i++)
{cout<<i;
if(i%5==0)
cout<<endl;};
}
void main()
{int m;
m=sum();
cout<<m<<endl;
show();}
这是第一，二题目