#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<math.h>

isprime(int n);
void save();

int main()
{
 int i,j,n;
 isprime(n);
 save();
 return 0;
}


isprime(int n)
 {
       int m,k,i,j=0,sum=0;
       printf("1000以内的素数是：\n");
       for(m=999;m>=1;m=m-2)
       {
           k=sqrt(m);
           for(i=2;i<=k;i++)
               if(m%i==0)
                   break;
           if(i>=k+1)
           {
               j++;
               sum+=m;

           printf("%8d",m);
           }
         
       }
       printf("\n");
       return ;
}


void save()
{
 FILE*fp;
 int i;
 if((fp=fopen("d:\\test1.txt","w"))==NULL)
 {
  printf("文件打开错误\n");
  return;
 }
 fclose(fp);

}