Run Length Encoding

游程编码 (Run Length Encoding ) 是一种简单的编码方法，通常用于控制论中对二值图像编码。ACM有一道题目就是关于该编码。见tzu 1149 或poj 1782 。虽然是简单题，我却花了好大功夫才搞定，功力还是不足阿。

程序代码如下：

#include <stdio.h>

#define MAX 1024

int printStr(char *str, int len);
int main(void)
{
  char target[MAX];
  int diffCount,sameCount;
  char *pFirstChar, *pLastChar;
  while(1)
    {
      if(fgets(target,sizeof(target),stdin) == NULL)
	break;
      pFirstChar = pLastChar = target;
      while(*pLastChar != '\n')
	{
	  diffCount = 0;
	  sameCount = 1;
	  /*if(*(pLastChar+1) == '\n')
	    {
	      printStr(pLastChar,1);
	      pLastChar++;
	    }
	    else*/
	  if(*pLastChar == *(pLastChar + 1))
	    {
	      while(*pLastChar == *(pLastChar + 1) &&sameCount <= 8)
		{
		  sameCount++;
		  pLastChar++;
		}
	      printf("%d%c",sameCount,*pLastChar);
	      pLastChar++;
	      pFirstChar = pLastChar;
	    }
	  else
	    {
	      while(*pLastChar != '\n' && *pLastChar != *(pLastChar + 1))
		{
		  diffCount++;
		  pLastChar++;
		}
	      printStr(pFirstChar,diffCount);
	      /*	      printf("\n");*/
	      pFirstChar =  pLastChar;
	    }
	}
      if(*pLastChar == '\n')
	putchar('\n');
    }
  return 0;
}
int printStr(char *str, int len)
{
  int i;
  putchar('1');
  for(i = 0; i < len; i++)
    if(*(str+i) == '1')
      printf("11");
    else
      putchar(*(str+i));
  putchar('1');
  return 0;
}