Huffman 编码器与解码器

[jongsuny]

Huffman 编码器与解码器 我想要最详细的
最好有几个具体的例子,具体的过程。
明天要交作业,不是本人的题,朋友的
可是我也不会..所以像高手求助..望高手给我做个详细的答案..

#include <iostream.h>
#include <iomanip.h>
#include <string.h>
#include <malloc.h>
const N=8;//??????????????????????????
typedef struct
{
int weight;
int parent,lchild,rchild;
}HTNode,*HuffmanTree;
typedef char **HuffmanCode;
void HuffmanCoding(HuffmanTree &HT,HuffmanCode &HC,int *w,int n);
void Select(HuffmanTree &HT,int i,int &s1,int &s2);
void DisplayHT(HuffmanTree HT,HuffmanCode HC);
void HuffmanCoding(HuffmanTree &HT,HuffmanCode &HC,int *w,int n)
{
int m,i,s1,s2;
HuffmanTree p;
if(n <=1)return ;
m=2*n-1;
HT=(HuffmanTree)malloc((m+1)*sizeof(HTNode));//0号单元未用
for(p=HT+1,i=1;i <=n;++i,++p,++w)//初始化HT[1...N]
{
p-> weight=*w;p-> parent=0;
p-> lchild=0;p-> rchild=0;
}

for(;i <=m;++i,++p)//初始化HT[N+1...M]
{
p-> weight=0;p-> parent=0;
p-> lchild=0;p-> rchild=0;
}
DisplayHT(p,HC);
for(i=n+1;i <=m;++i)//建哈夫曼树
{//在HT[1...i-1]中选择两个其双亲域为零而权值取最小的结点，
//它们在HT中的序号分别为S1和S2
Select(HT,i-1,s1,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;
}
//---从叶子到根逆向求每个字符的哈夫曼编码----
HC=(HuffmanCode)malloc((n+1)*sizeof(char));//分配N个字符的头指针向量
char *cd;
cd=(char*)malloc(n*sizeof(char));//分配求编码的工作空间
cd[n-1]='\0'; //编码结束符
int start;
for(i=1;i <=n;++i) //逐个字符求哈夫曼编码
{
start=n-1; //编码结束符位置
for(int c=i,f=HT[i].parent;f!=0;c=f,f=HT[f].parent)
{//从叶子到根逆向求每个字符的哈夫曼编码
if(HT[f].lchild==c)
cd[--start]='0';
else
cd[--start]='1';
}//为第I个字符编码分配空间
HC[i]=(char*)malloc((n-start)*sizeof(char));
strcpy(HC[i],&cd[start]);//从CD复制编码串到HC
cout < <HC[i] < <endl;
}
free(cd);
}
void Select(HuffmanTree &HT,int i,int &s1,int &s2)
{//选择森林中根结点的值最小和次小的两个树，将其根结点的下标号记入S1和S2中
for(int k=1;k <=i;k++)
if(HT[k].parent==0)
{
s1=k;
s2=k;
break;
}
for(;k <=i;k++)
if(HT[k].parent==0 && HT[k].weight <HT[s1].weight)
s1=k;
if(s1==s2)
s2++;
for(k=s2;k <=i;k++)
if(HT[k].parent==0)
{
s2=k;
break;
}
for(;k <=i;k++)
if(k!=s1)
if(HT[k].parent==0 && HT[k].weight <HT[s1].weight)
s2=k;//S2中存放权值次小的根结点的下标号
if(s1> s2)
{
int temp=s1;
s1=s2;
s2=temp;
}
}
void DisplayHT(HuffmanTree HT,HuffmanCode HC)
{
cout < <"HT:" < <endl;
cout < <" weight parent lchild rchild" < <endl;
for(int i=1;i <=2*N-1;i++)
cout < <setw(8) < <HT[i].weight < <setw(8) < <HT[i].parent
< <setw(8) < <HT[i].lchild < <setw(8) < <HT[i].rchild < <endl;
cout < <"HC:" < <endl;
for(i=1;i <=N;i++)
cout < <setw(5) < <HT[i].weight < <": " < <HC[i] < <endl;
}
int main()
{
HuffmanTree HT;
HuffmanCode HC;
int w[N];
cout < <endl < <"please input the weight" < <endl;
for(int i=0;i <N;i++)
{
cout < <i+1 < <":";
cin> > w[i];
}
HuffmanCoding(HT,HC,w,N);;
cout < <endl;
DisplayHT(HT,HC);
cout < <endl;
return 0;
}


这个程序哪里出错了啊?
请高手指点..

[jongsuny]

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <malloc.h>
#include <conio.h>

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)
{

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++)
{
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=1;i<=m;i++)
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=1;i<=n;i++)
{
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=1;i<=n;i++)
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;
}

void main()
{
HuffmanTree HT=NULL;
HuffmanCode HC=NULL;
unsigned int *w=NULL;
unsigned int i,n;

printf("Input n:\n");
scanf("%d",&n);
w=(unsigned int *)malloc((n+1)*sizeof(unsigned int *));
w[0]=0;
printf("Enter weight:\n");
for(i=1;i<=n;i++)
{
printf("w[%d]=",i);
scanf("%d",&w[i]);
}
HC=HuffmanCoding(HT,HC,w,n);
printf("HuffmanCode:\n");
printf("Number\t\tWeight\t\tCode\n");
for(i=1;i<=n;i++)
printf("%d\t\t%d\t\t%s\n",i,w[i],HC[i]);

}
哎..还是我自己回答.. 也是一种乐趣啊..哈哈