技术文章 > 霍夫曼树编码的实现

霍夫曼树编码的实现

2018-02-24 20:14

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#include
#include
#include
#include
typedef struct
{
unsigned int Weight;
unsigned int Parent;
unsigned int lChild;
unsigned int rChild;
}HTNode,*HuffmanTree;
typedef char **HuffmanCode;
int LookFor(char *str,char letter,int count);
void OutputWeight(char *Data,int Length,
char **WhatLetter,
int **Weight,int *Count);
void HuffmanCoding(HuffmanTree *HT,
HuffmanCode *HC,
int *Weight,
int Count);
void Select(HuffmanTree HT,int Count,int *s1,int *s2);
int main()
{
HuffmanTree HT;
HuffmanCode HC;
char Data[100];
char *WhatLetter;
int *Weight;
int Count;
int i;
printf("Please input the line:");
/* Example: aaaaaaaaaaaaaabcccccc*/
scanf("%s",Data);
printf("\n");
OutputWeight(Data,strlen(Data),
&WhatLetter,
&Weight,
&Count);
HuffmanCoding(&HT,&HC,Weight,Count);
printf(" Letter Weight Code\n");
for(i=0;i {
printf(" %c ",WhatLetter[i]);
printf("%d ",Weight[i]);
printf("%s\n",HC[i+1]);
}
printf("\n");
getch();
return 0;
}
void HuffmanCoding(HuffmanTree *HT,
HuffmanCode *HC,
int *Weight,
int Count)
{
int i;
int s1,s2;
int TotalLength;
HuffmanTree p;
char* cd;
unsigned int c;
unsigned int f;
int start;
if(Count<=1) return;
TotalLength=Count*2-1;
(*HT)=(HuffmanTree)malloc((TotalLength+1)*sizeof(HTNode));
p=((*HT)++);
for(i=1;i<=Count;i++)
{
(*HT)[i].Parent=0;
(*HT)[i].rChild=0;
(*HT)[i].lChild=0;
(*HT)[i].Weight=(*Weight);
Weight++;
}
for(i=Count+1;i<=TotalLength;i++)
{
(*HT)[i].Weight=0;
(*HT)[i].Parent=0;
(*HT)[i].lChild=0;
(*HT)[i].rChild=0;
}
/*///////////////////Create HuffmanTree////////////////*/
for(i=Count+1;i<=TotalLength;++i)
{
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;
}
/*///////////////////Output Huffman Code///////////////*/
(*HC)=(HuffmanCode)malloc((Count+1)*sizeof(char*));
cd=(char*)malloc(Count*sizeof(char));
cd[Count-1]=“\0“;
for(i=1;i<=Count;++i)
{
start=Count-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((Count-start)*sizeof(char));
strcpy((*HC)[i],&cd[start]);
}
}
}
void Select(HuffmanTree HT,int Count,int *s1,int *s2)
/*/(*s1) is smallest,(*s2) is smaller.*/
{
int i;
unsigned int temp1=0;
unsigned int temp2=0;
unsigned int temp3;
for(i=1;i<=Count;i++)
{
if(HT[i].Parent==0)
{
if(temp1==0)
{
temp1=HT[i].Weight;
(*s1)=i;
}
else
{
if(temp2==0)
{
temp2=HT[i].Weight;
(*s2)=i;
if(temp2 {
temp3=temp2;
temp2=temp1;
temp1=temp3;
temp3=(*s2);
(*s2)=(*s1);
(*s1)=temp3;
}
}
else
{
if(HT[i].Weight {
temp2=temp1;
temp1=HT[i].Weight;
(*s2)=(*s1);
(*s1)=i;
}
if(HT[i].Weight>temp1&&HT[i].Weight {
temp2=HT[i].Weight;
(*s2)=i;
}
}
}
}
}
}
int LookFor(char *str,char letter,int count)
{
int i;
for(i=0;i {
if(str[i]==letter) return i;
}
return -1;
}
void OutputWeight(char *Data,int Length,
char **WhatLetter,
int **Weight,int *Count)
{
int i;
char* Letter=(char*)malloc(Length);
int* LetterCount=(int *)malloc(Length);
int AllCount=0;
int Index;
int Sum=0;
float Persent=0;
for(i=0;i {
if(i==0)
{
Letter[0]=Data[i];
LetterCount[0]=1;
AllCount++;
}
else
{
Index=LookFor(Letter,Data[i],AllCount);
if(Index==-1)
{
Letter[AllCount]=Data[i];
LetterCount[AllCount]=1;
AllCount++;
}
else
{
LetterCount[Index]++;
}
}
}
for(i=0;i {
Sum=Sum+LetterCount[i];
}
(*Weight)=(int*)malloc(AllCount);
(*WhatLetter)=(char*)malloc(AllCount);
for(i=0;i {
Persent=(float)LetterCount[i]/(float)Sum;
(*Weight)[i]=(int)(1000*Persent);
(*WhatLetter)[i]=Letter[i];
}
(*Count)=AllCount;
}