huffmanuncoding.c

哈夫曼编码解码以及文档资料和Makefile文件。

#include "head.h"
#include "struct.h"
#include "declare.h"

int HuffmanUncoding(HuffmanTree HT,char *filename,CharArr *ch)//译码
{
	FILE *code,*uncode;
	char uncodename[]="uncodefile";
	char c;
	int m,n,i;
	HuffmanTree p;
	int s1=0,s2=0;

#if 1
	int j;
#endif

	code=fopen(filename,"rt");
	if(code==NULL)
	{
		fprintf(stderr,"open file fail:%s",strerror(errno));
		return -1;
	}
	uncode=fopen(uncodename,"wt");
	if(uncode==NULL)
	{
		fprintf(stderr,"creat file fail:%s",strerror(errno));
		return -1;
	}
	if(ch->size<1)
		return -1;
	n=ch->size;
	m = 2*n-1;
	HT=(HuffmanTree)malloc((m+1)*sizeof(HTNode));
	for(p=HT+1,i=1;i<=n;++i,++p)
	{
		p->s=ch->e[i-1].c;
		p->weight=ch->e[i-1].w;
		p->parent=0;
		p->lchild=0;
		p->rchild=0;
	}
	for(;i<=m;++i,++p)
	{
		p->s='\0';
		p->weight=0;
		p->parent=0;
		p->lchild=0;
		p->rchild=0;
	}
	for(i=n+1;i<=m;++i)
	{
		SelectMin(HT,i-1,&s1,&s2);
		HT[s1].parent=i;
		HT[s2].parent=i;
		if(s1<=s2)
		{
			HT[i].lchild=s1;
			HT[i].rchild=s2;
		}
		else
		{
			HT[i].lchild=s2;
			HT[i].rchild=s1;
		}
		HT[i].weight = HT[s1].weight+HT[s2].weight;
	}	
	

	//p=HT+m;
	//printf("\t%d\t%d\t%d\t%d\n",p->weight,p->parent,p->lchild,p->rchild);
	
	#if 1
	for(p=HT+1,j=0;p->parent!=0||j<m;p++,j++)
		printf("\t%d\t%d\t%d\t%d\n",p->weight,p->parent,p->lchild,p->rchild);
	#endif
	
	for(c=fgetc(code),p=HT+m;!feof(code);p=HT+m)
     {
        for(;p->lchild&&p->rchild;c=fgetc(code))//从根出发至叶子节点
        {
        	//printf("%c",c);
             if(c=='0')
                 p=HT+p->lchild;
             else if(c=='1')
                 p=HT+p->rchild;
        }
        if(!p-> lchild&&!p->rchild)
        {
        	for(i=0;i<ch->size;i++)
			{
				if((p->weight==ch->e[i].w)&&(p->s==ch->e[i].c))
				{
					fprintf(uncode,"%c",ch->e[i].c);
					//printf("\t%c\n",ch->e[i].c);
					//getchar();
				}
			}
        }
     }
	fclose(uncode);
	fclose(code);
	return 0;
}