哈夫曼树实验报告需求分析：从终端读入一串字符，利用建立好的哈夫曼树对其进行编码，储存到文件当中去，然后从文件读入哈夫曼编码，针对每个字母对其进行译码，翻译为原来的信息。

二、概要设计程序分为以下几个模块：1、从终端读入字符集大小，n个字符和n个权值，建立哈夫曼树，写入文件hfmTree中去。

2、对hfmTree进行编码，建立hfm编码表。

3、从文件ToTran读入信息，根据hfm编码表对其进行hfm编码，将编码后的信息写入文件Codefile 中去4、对Codefile文件反向译码，结果储存在Textfile中去。

5、将建立的hfmTree打印在终端上，并储存于相应的Treeprint文件中去。

抽象的数据定义如下：哈夫曼树结构typedef struct //定义哈夫曼树的结构{int weight; //权值int parent; //双亲int lchild; //左孩子int rchild; //右孩子}htnode,huffmantree[M+1];建立哈夫曼树void crthuffmantree(huffmantree ht,int w[],int n) //初始化哈夫曼树{int i,s1,s2,m;for(i=1;i<=n;i++){ht[i].weight=w[i];ht[i].parent=0;ht[i].lchild=0;ht[i].rchild=0;}m=2*n-1;for(i=n+1;i<=m;i++){ht[i].weight=0;ht[i].parent=0;ht[i].lchild=0;ht[i].rchild=0;}for(i=n+1;i<=m;i++){select(ht,i-1,&s1,&s2);ht[i].weight=ht[s1].weight+ht[s2].weight;ht[s1].parent=i;ht[s2].parent=i;ht[i].lchild=s1;ht[i].rchild=s2;}}typedef char *huffmancode[N+1]; //建立哈夫曼树编码表void crthuffmancode(huffmantree ht,huffmancode hc,int n){char *cd; //新建立一个指针int start,i,c,p;cd=(char*)malloc(n*sizeof(char))；//分配求一个字符的哈夫曼编码的空间cd[n-1]='\0'; //编码结束符for(i=1;i<=n;i++){start=n-1;c=i;p=ht[i].parent;while(p!=0){--start;if(ht[p].lchild==c)cd[start]='0';elsecd[start]='1';c=p;p=ht[p].parent;}hc[i]=(char *)malloc((n-start)*sizeof(char));strcpy(hc[i],&cd[start]);}free(cd);}select(huffmantree ht,int pos,int *s1,int *s2) //取最小和次小权值{int j,m1,m2;m1=m2=maxint;for(j=1;j<=pos;j++){if(ht[j].weight<m1&&ht[j].parent==0) //定义为双亲为零时才开始求，这样就做到了防止筛选过的重新加入比较列表里{m2=m1;*s2=*s1;*s1=j;m1=ht[j].weight;}else if(ht[j].weight<m2&&ht[j].parent==0){m2=ht[j].weight;*s2=j;}}}主程序模块int main(){初始化参数printf("请输入：初始化 I;编码 E;译码 D;印代码文件 P;印哈弗曼树 T\n");printf("结束请输入Q\n");while(1){ //这就是用户输入scanf("%c",&q);if(q=='Q'){break;}if(q=='I'){fpw=fopen("hfmtree.txt","w");ftest=fopen("date.txt","r");printf("请输入密码表，第一位表示密码表大小，之后按空格键开始以紧凑的格式输入编码字母和权值。

\n");scanf("%d",&n); //字符集大小输入getchar(); //吃空格用的for(i=1;i<=n;i++) //这里本来是要在终端输入的，我为了图个测试方便就写文件里，可以自己改回来{fscanf(ftest,"%c",&a);if(a!='\n'){str[i]=a;fscanf(ftest,"%d",&weight[i]);}else i--; //减去回车键的计数，应该是用于输入量过多情况下需要隔行输入的设定}for(i=n+1;i<=2*n-1;i++) //补全剩余的{str[i]='0';}crthuffmantree(ht1,weight,n); //建立哈夫曼树crthuffmancode(ht1,hc1,n); //建立哈夫曼编码表for(i=1;i<=2*n-1;i++) //打印到文件中去{fprintf(fpw,"%c %d %d %d %d\n",str[i],ht1[i].weight,ht1[i].parent,ht1[i].lchild,ht1 [i].rchild);}fclose(ftest); //关闭文件，这点很重要，否则文件不会写入fclose(fpw);}if(q=='E'){j=1;i=1;fpr=fopen("tobetran.txt","r");fpr2=fopen("hfmtree.txt","r");fpw2=fopen("codefile.txt","w");while(fscanf(fpr2,"%c %d %d %d %d\n",&str[j],&ht1[j].weight,&ht1[j].parent,&ht1[j]. lchild,&ht1[j].rchild)!=EOF){j++; //计数，哈夫曼树值大小}while(fscanf(fpr,"%c",&dst[i])!=EOF){i++; //所输入文件字符大小}count=j; //count代表就是哈夫曼树大小，count1代表输入文件大小count1=i;crthuffmancode(ht1,hc1,count-1); //重新从文件里建立哈夫曼编码表for(i=1;i<=count1-1;i++){for(j=1;j<=count/2;j++) //count/2就是字符集大小了{if(dst[i]==str[j]) //比较{fprintf(fpw2,"%s",hc1[j]); //找到后写入对应的编码到文件中去，也就是codefile那个文件}}}fclose(fpr);fclose(fpr2);fclose(fpw2);}if(q=='D'){j=1;i=1;z=1;fpr2=fopen("hfmtree.txt","r");fpr3=fopen("codefile.txt","r");fpw3=fopen("textfile.txt","w");while(fscanf(fpr3,"%c",&dst[i])!=EOF){i++;}count3=i;while(fscanf(fpr2,"%c %d %d %d %d\n",&str[j],&ht1[j].weight,&ht1[j].parent,&ht1[j].lchi ld,&ht1[j].rchild)!=EOF){j++;}count2=j; //count2是哈夫曼树大小计数，count3是读入的哈夫曼编码计数crthuffmancode(ht1,hc1,count2-1); //重新建立哈夫曼编码表for(i=1;i<count3;i++){for(j=1;j<=count2/2;j++){len=strlen(hc1[j]); //对每个字符哈夫曼编码长度统计for(t=0;t<len;t++){if(hc1[j][t]==dst[t+i]) //这里就相当字符匹配了{flag=1;}if(hc1[j][t]!=dst[t+i]){flag=0;break;}}if(flag==1&&t==len) //判断{win[z]=str[j]; //写入字符z++;i=i+len-1;break;}}}count4=z;for(z=1;z<count4;z++) //写入文件中{fprintf(fpw3,"%c",win[z]);}fclose(fpr2);fclose(fpr3);fclose(fpw3);}if(q=='P') //打印codefile文件{j=1;fpr2=fopen("codefile.txt","r");fpw3=fopen("codeprin.txt","w");while(fscanf(fpr2,"%c",&dst[j])!=EOF){j++;}count=j;j=0;for(i=1;i<count;i++){j++;if(j==50){printf("\n");j=0;}printf("%c",dst[i]);fprintf(fpw3,"%c",dst[i]);}fclose(fpr2);fclose(fpw3);}if(q=='T') //打印哈夫曼树，完备的树结构不好打印，这里就是通过本身结构大致打印出来{fpw=fopen("treeprin.txt","w");fpr=fopen("hfmtree.txt","r");i=1;m=0;while(fscanf(fpr,"%c %d %d %d %d\n",&str[i],&ht1[i].weight,&ht1[i].parent,&ht1[ i].lchild,&ht1[i].rchild)!=EOF){m++;i++;}n=(m+1)/2; //字符集大小maxlen=0; //最大字符编码长度crthuffmancode(ht1,hc1,n); //重新建立哈夫曼编码表for(i=1;i<=n;i++){len=strlen(hc1[i]);if(maxlen<len)maxlen=len;}count=maxlen; //求得最大字符编码长度，用来控制行数的for(i=1;i<=m;i++){t=0;if(ht1[i].parent==0) //先寻找根节点，打印出来{for(c=0;c<2*count;c++) //打印空格{printf(" ");fprintf(fpw," ");}printf("%d\n",ht1[i].weight);fprintf(fpw,"%d\n",ht1[i].weight);count=count-1; //跳入下一行j=ht1[i].lchild;low[t]=j; /记录根节点右子树，用数组low[]t++;k=ht1[i].rchild; //记录根节点左子树low[t]=k;t++;for(c=0;c<2*count;c++) //打空格{printf(" ");fprintf(fpw," ");}printf("%d ",ht1[j].weight);//打印根节点的右子树和左子树fprintf(fpw,"%d ",ht1[j].weight);printf(" ");fprintf(fpw," ");printf("%d\n",ht1[k].weight);fprintf(fpw,"%d\n",ht1[k].weight);count=count-1;}}p=0;while(p<maxlen-2) //p来控制打印的结束标志{for(j=0;j<2*count;j++){printf(" ");fprintf(fpw," ");}y=t; //y作为每一行节点数的记录用t=0;for(i=0;i<y;i++) //下面就是一个循环过程{if(ht1[low[i]].lchild!=0){printf("%d ",ht1[ht1[low[i]].lchild].weight);fprintf(fpw,"%d ",ht1[ht1[low[i]].lchild].weight);}else{printf("0 ");fprintf(fpw," ");}if(ht1[low[i]].rchild!=0){printf("%d ",ht1[ht1[low[i]].rchild].weight);fprintf(fpw,"%d ",ht1[ht1[low[i]].rchild].weight);}else{printf("0 ");fprintf(fpw," ");}if(ht1[low[i]].lchild!=0) //记录本层的孩子数量和位置，用数组d[] {d[t]=ht1[low[i]].lchild;t++;}if(ht1[low[i]].rchild!=0){d[t]=ht1[low[i]].rchild;t++;}}for(i=0;i<t;i++) //转移{low[i]=d[i];}printf("\n");p++;count=count-1;}fclose(fpw); //记住关文件fclose(fpr);}}return 0;}函数的调用关系MianCrthuffmancode crthuffmantree select设计和调试分析1、打印树本来是考虑用严格格式输出，但是需要空间太大，就用类似树的形式输出2、文件操作最后必须要关闭文件，否则会一直在缓冲区中3、注意关闭指针用户手册用户界面如下用户需要预先准备好totran文件，然后根据提示输入字符集大小和每个字母和对应的权值，然后按E编译代码，D印刷代码，P打印哈夫曼树到文件和终端上。