程序代码：

//小于c1的直接输出，大于的就减去c1，得到的就是复制的字节数，后面跟着的是回退量
#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
void main()
{
 FILE *fa,*fb;
 if((fa=fopen("1.GRC","rb"))==NULL)
 {printf("cannot open file A\n");exit(0);}
 if((fb=fopen("0.bin","wb+"))==NULL)
 {printf("cannot open file C\n");exit(0);}

 unsigned char j[65];
 unsigned char ah,bh;
 while (!feof(fa))
{
   ah=fgetc(fa);
   bh=fgetc(fa);


/********ah小于c1，bh小于c1******/
  if (ah<0xc1 && bh<0xc1)
  {if (!feof(fa))
   {fputc(ah,fb);
    fputc(bh,fb);}
  }


/***********ah小于c1，bh等于c1************/
  else if (ah<0xc1 && bh==0xc1)
  {if (!feof(fa))
   {   fputc(ah,fb);
       ah=fgetc(fa);
       fputc(ah,fb);}
  }

 /**************ah小于c1，bh大于c1***********/
  else if (ah<0xc1 && bh>0xc1)
  {
   if (!feof(fa))
   {   fputc(ah,fb);
       ah=fgetc(fa);
       fseek(fb,-ah,1);
       fread(&j,1,bh-0xC0,fb);
       fseek(fb,0,2);
       fwrite(&j,1,bh-0xC0,fb);
   }
  }


/************ah等于c1**************/
  else if (ah==0xc1)
  {if (!feof(fa))
  {fputc(bh,fb);}}


/******************ah大于c1*******************/
  else if (ah>0xc1)
  {
   if (!feof(fa))
   {   fseek(fb,-bh,1);
       fread(&j,1,ah-0xC0,fb);
       fseek(fb,0,2);
       fwrite(&j,1,ah-0xC0,fb);
   }
  }
 }
 fclose(fa);
 fclose(fb);
}