C语言实现哈夫曼编码

/*先根据位权构造一颗哈夫曼树，测试数据0.050.10.150.20.250.25，再从叶子结点到根结点编码。程序结果保存在out.dat中。*/#includestdio.h#includestdlib.h#includestring.h#defineN6typedefstruct{doubleweight;intparent,lchild,rchild;}HuffmanTree;voidSelect(HuffmanTree*HT,inti,int*s1,int*s2){intn,T=0,T1;for(n=1;ni;n++)if((HT[n].weight=HT[T].weight)&&HT[n].parent==0)T=n;*s1=T;T1=T;T=0;for(n=1;ni;n++){if(n==T1)continue;if((HT[n].weight=HT[T].weight)&&HT[n].parent==0)T=n;}*s2=T;}voidHuffmanCoding(HuffmanTree*HT,char**HC,double*w,intn){intm,i,start;ints1,s2,f,c;char*cd;HuffmanTree*p;if(n=1)return;m=2*n-1;HT[0].weight=10000;w++;for(p=HT+1,i=1;i=n;++i,++w,++p){p-weight=*w;p-lchild=0;p-rchild=0;p-parent=0;}for(;i=m;++i,++p){p-weight=0;p-lchild=0;p-rchild=0;p-parent=0;}for(i=n+1;i=m;++i){Select(HT,i,&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;}cd=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]='1';elsecd[--start]='0';HC[i]=(char*)malloc((n-start)*sizeof(char));strcpy(HC[i],&cd[start]);}free(cd);}voidmain(){HuffmanTree*HT;inti;char**HC;doublew[N+1];floattemp;FILE*fp1,*fp2;HT=malloc((N)*sizeof(HuffmanTree));HC=malloc((N+1)*sizeof(char*));if((fp1=fopen(in.dat,rb))==NULL){printf(不能打开文件！\n);exit(1);}if((fp2=fopen(out.dat,a))==NULL){printf(不能打开文件！\n);exit(1);}for(i=1;i=N;i++){fscanf(fp1,%f,&temp);w[i]=temp;}fclose(fp1);HuffmanCoding(HT,HC,w,N);for(i=1;i=N;i++){fprintf(fp2,%f的Huffman编码为：%s\n,w[i],HC[i]);}fclose(fp2);printf(编码成功!\n);}/*文件in.dat内容：0.050.10.150.20.250.25*/