c++第四次作业

#include<iostream.h>
void main()
{
int i(0),sum(0);
while(i<=1000)
{
sum=sum+i;
i=i+2;
}
cout<<"1000以内所有偶数的和为:"<<sum<<endl;
}

#include<iostream.h>
void main()
{
int i(0),sum(0);
do
{
sum+=i;
i=i+2;
}while(i<=1000);
cout<<"1000以内所有偶数的和为:"<<sum<<endl;
}

#include<iostream.h>
void main()
{
int i(0),sum(0);
for(i=0;i<=1000;i=i+2)sum=sum+i;
cout<<"1000以内所有偶数的和为:"<<sum<<endl;
}

#include<iostream.h>
void main()
{
int i,j;
for(i=1;i<=9;i++)
{
for(j=1;j<=i;j++)
{
cout<<i<<"*"<<j<<"="<<i*j<<"  ";
}
cout<<endl;
}
}

#include<iostream.h>
int main()
{
int i,j;
for (i=0;i<5;i++)
{
for (j=0;j<5-i;j++)
cout<<" ";
for (j=0;j<1;j++)
cout<<"*";
for (j=0;j<=2*i-2;j++)
cout<<" ";
if(i!=0)
cout<<"*";
cout<<endl;
}
for (i=0;i<11;i++)
cout<<"*";
cout<<endl;
}