1_pro.c

来自「C源代码 计算机等级考试C语言上机题」· C语言 代码 · 共 37 行

#include  <conio.h>
#include  <math.h>
#include  <stdio.h>
double countvalue(int n)
{
  double xy=0.0;
  int i;
  for(i=1;i<n;i++)
    if(i%3==0&&i%7==0)  xy+=i;
  xy=sqrt((double)xy);
  return xy;
}
main()
{
  clrscr();
  printf("自然数之和的平方根=%f\n",countvalue(1000));
  progReadWrite();
}
progReadWrite()
{
  FILE *fp,*wf;
  int i,n;
  float s;
  fp=fopen("IN94.DAT","r");
  if(fp==NULL)
  { printf("数据文件IN94.DAT不存在!"); return; }
  wf=fopen("OUT94.DAT","w");
  for(i=0;i<10;i++)
  {
    fscanf(fp,"%d\n",&n);
    s=countvalue(n);
    fprintf(wf,"%f\n",s);
  }
  fclose(fp);
  fclose(wf);
}