基于霍夫曼算法的文件压缩

小弟现在做毕业设计，用C语言做基于霍夫曼算法的文件压缩。要求是从一篇文章中读取每个字符，然后统计字符个数，再根据字符个数建造霍夫曼树，并编成0，1代码。源程序如下，请各位高手指点以下，因为我的程序执行后的结果有错误。words.txt文件在程序后面。请大家快快帮忙啊，小弟现在非常着急，谢谢各位了！

 #include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <malloc.h>
#include <conio.h>
/*#define  N 26*/

typedef struct
{
 unsigned int weight;
 unsigned int parent,lchild,rchild;
} HTNode,*HuffmanTree;

typedef char **HuffmanCode;

typedef struct {
 unsigned int s1;
 unsigned int s2;
} MinCode;

void Error(char *message);

HuffmanCode HuffmanCoding(HuffmanTree HT,HuffmanCode HC,unsigned int *w,unsigned int n);

MinCode Select(HuffmanTree HT,unsigned int n);

void Error(char *message)
{
 clrscr();
 fprintf(stderr,"Error:%s/n",message);
 exit(1);
}

HuffmanCode HuffmanCoding(HuffmanTree HT,HuffmanCode HC,unsigned int *w,unsigned int n)
{
 unsigned int i,s1=0,s2=0;
 HuffmanTree p;
 char *cd;
 unsigned int f,c,start,m;
 MinCode min;
 if(n<=1) Error("Code too small!");
 m=2*n-1;
 HT=(HuffmanTree)malloc((m+1)*sizeof(HTNode));
 for(p=HT,i=0;i<=n;i++,p++,w++)/************i<=n**************/
 {
  p->weight=*w;
  p->parent=0;
  p->lchild=0;
  p->rchild=0;
 }
 for(;i<=m;i++,p++)
  {
    p->weight=0;
    p->parent=0;
    p->lchild=0;
    p->rchild=0;
  }
 for(i=n+1;i<=m;i++)/************************/
  {
    min=Select(HT,i-1);
    s1=min.s1;
    s2=min.s2;
    HT[s1].parent=i;
    HT[s2].parent=i;
    HT[i].lchild=s1;
    HT[i].rchild=s2;
    HT[i].weight=HT[s1].weight+HT[s2].weight;
  }

  printf("HT List:/n");
  printf("Number/t/tweight/t/tparent/t/tlchild/t/trchild/n");

 for(i=0;i<=m;i++)/*************0->1*************************************/
   printf("%d/t/t%d/t/t%d/t/t%d/t/t%d/n",
     i,HT[i].weight,HT[i].parent,HT[i].lchild,HT[i].rchild);

  HC=(HuffmanCode)malloc((n+1)*sizeof(char *));
  cd=(char *)malloc(n*sizeof(char *));
  cd[n-1]='/0';
 for(i=0;i<=n;i++)/*******!!!1---n***********************/
 {
 start=n-1;/*************************************/
   for(c=i,f=HT[i].parent;f!=0;c=f,f=HT[f].parent)
  if(HT[f].lchild==c) cd[--start]='0';
  else cd[--start]='1';
   HC[i]=(char *)malloc((n-start)*sizeof(char *));
   strcpy(HC[i],&cd[start]);
  }
  free(cd);
  return HC;
}

MinCode Select(HuffmanTree HT,unsigned int n)
{
  unsigned int min,secmin;
  unsigned int temp;
  unsigned int i,s1,s2,tempi;
  MinCode code;
  s1=1;s2=1;
 for(i=0;i<=n;i++)/*****!!!!***1---n*************/
   if(HT[i].parent==0)
   {
   min=HT[i].weight;
   s1=i;
   break;
   }
  tempi=i++;
 for(;i<=n;i++)/*************************************/
  if(HT[i].weight<min&&HT[i].parent==0)
  {
   min=HT[i].weight;
   s1=i;
  }
 for(i=tempi;i<=n;i++)/********************************/
   if(HT[i].parent==0&&i!=s1)
   {
   secmin=HT[i].weight;
   s2=i;
   break;
   }
 for(i=1;i<=n;i++)/***********************************/
  if(HT[i].weight<secmin&&i!=s1&&HT[i].parent==0)
  {
   secmin=HT[i].weight;
   s2=i;
  }
  if(s1>s2)
  {
    temp=s1;
    s1=s2;
    s2=temp;
  }
  code.s1=s1;
  code.s2=s2;
  return code;
}
main()
{
 HuffmanTree HT=NULL;
  HuffmanCode HC=NULL;
 unsigned int num[26];
 unsigned int n=26;
 char ch;
 char zifu[800];
 int  i;
 char c;
 FILE *fp;
 clrscr();
 if((fp=fopen("words.txt","r"))==NULL)
 {
  printf("open file error!--words.txt/n");
  exit(0);
 }
 if((ch=fgetc(fp))==EOF)
 {
  printf("/nempty file!");
 }
 zifu[0]=ch;
 if((ch!=EOF)&&(ch>='A'&&ch<='Z')||(ch>='a'&&ch<='z'))
 {
  for(i=1;i<800;i++)
  {
   ch=fgetc(fp);
   zifu[i]=ch;
  }
 }
 for(i=0;i<800;i++)
 {
  if(zifu[i]!='/0')
  printf("%c",zifu[i]);
 }
 printf("/n");
 fclose(fp);
 printf("press anykey,go on...");
 getchar();
 printf("/n");
 for(i=0;i<n;i++)/*******************/
 {
  num[i]=0;
 }
 for(i=0;(c = zifu[i])!='/0';i++)
 {
  if (tolower(c) =='a')
  {
   num[0]=num[0]+1;
  }
  if (tolower(c)=='b')
  {
   num[1]=num[1]+1;
  }
  if (tolower(c) =='c')
  {
   num[2]=num[2]+1;
  }
  if (tolower(c)=='d' )
  {
   num[3]=num[3]+1;
  }
  if (tolower(c) =='e')
  {
   num[4]=num[4]+1;
  }
  if (tolower(c) =='f')
  {
   num[5]=num[5]+1;
  }
  if (tolower(c) =='g')
  {
   num[6]=num[6]+1;
  }
  if (tolower(c) =='h')
  {
   num[7]=num[7]+1;
  }
  if (tolower(c) =='i')
  {
   num[8]=num[8]+1;
  }
  if (tolower(c) =='j')
  {
   num[9]=num[9]+1;
  }
  if (tolower(c) =='k')
  {
   num[10]=num[10]+1;
  }
  if (tolower(c) =='l')
  {
   num[11]=num[11]+1;
  }
  if (tolower(c) =='m')
  {
   num[12]=num[12]+1;
  }
  if (tolower(c) =='n')
  {
   num[13]=num[13]+1;
  }
  if (tolower(c) =='o')
  {
   num[14]=num[14]+1;
  }
  if (tolower(c) =='p')
  {
   num[15]=num[15]+1;
  }
  if (tolower(c) =='q')
  {
   num[16]=num[16]+1;
  }
  if (tolower(c) =='r')
  {
   num[17]=num[17]+1;
  }
  if (tolower(c) =='s')
  {
   num[18]=num[18]+1;
  }
  if (tolower(c) =='t')
  {
   num[19]=num[19]+1;
  }
  if (tolower(c) =='u')
  {
   num[20]=num[20]+1;
  }
  if (tolower(c) =='v')
  {
   num[21]=num[21]+1;
  }
  if (tolower(c) =='w')
  {
   num[22]=num[22]+1;
  }
  if (tolower(c) =='x')
  {
   num[23]=num[23]+1;
  }
  if (tolower(c) =='y')
  {
   num[24]=num[24]+1;
  }
  if (tolower(c) =='z')
  {
   num[25]=num[25]+1;
  }
 }
 for(i=0;i<n;i++)/****************************/
 {
  printf("number of %c is:%2d",97+i,num[i]);
  printf("/n");
 }
 printf("/n");
 printf("press anykey,go on...");
 getchar();
 printf("/n");
 HC=HuffmanCoding(HT,HC,num,n);/************************/
 printf("/n");
 printf("press anykey,go on...");
 getchar();
 printf("/n");
  printf("HuffmanCode:/n");
  printf("Number/t/tWeight/t/tCode/n");
 for(i=0;i<n;i++)/******************/
 printf("%d/t/t%d/t/t%s/n",i,num[i],HC[i]);
 /*clrscr();*/
 HC=NULL;
 return 0;
}

words.txt  内容如下:

The central thematic concerns of Shelley's poetry are largely the same themes that defined Romanticism: beauty, the passions, nature, political liberty, creativity, and the sanctity of the imagination. What makes Shelley's treatment of these themes unique is his philosophical relationship to his subject matter—which was better developed and articulated than that of any other Romantic poet with the possible exception of Wordsworth—and his temperament which possessed an extraordinary capacity for joy, love, and hope. Shelley fervently believed in the possibility of realizing an ideal of human happiness as based on beauty, and his moments of darkness and despair almost always stem from his disappointment at seeing that ideal sacrificed to human weakness.