C++补做作业2

#include <iostream.h>
#include <fstream.h>
#include <stdio.h>
void writeinfile(int n);
void main()
{
int x,y,n;
x=25,y=10;
/**********Program**********/
n=x%y;
while(n)
{

x=y;
y=n;
n=x%y;
}

/**********  End  **********/
cout<<y;
writeinfile(y);
}
void writeinfile(int n)
{
fstream myfile;
myfile.open(" f.txt" ,ios::out);
myfile<<n<<endl;
myfile.close();
}

#include <iostream.h>

#include <fstream.h>

#include <stdio.h>

void writeinfile(int n);

void main()

{

int  n,k,m,l,sum=0;

n=100;

/**********Program**********/

for(k=2;k<=n;k++)

{
l=1;
for(m=2;m<k;m++)
{
if(k%m==0)
l=0;
}

if(l!=0)
sum+=k;

}

cout<<sum;

/**********  End  **********/

writeinfile(sum);

}

void writeinfile(int n)

{

fstream myfile;

myfile.open(" f.txt" ,ios::out);

myfile<<n<<endl;

myfile.close();

}