输入任意字符串，str[]={"a","b","c","d","e”,"f","g","h"}

Question

输入任意字符串，str[]={"a","b","c","d","e”,"f","g","h"},每种字符出现频率fnum[]={0.070.19,0.02,0.06,0.32,0.03,0.21,0.1},根据出现频率，利用哈夫曼编码原理，对每个字符进行（0.1）编码，并输出每种字符编码。
注意：写清具体步骤（文字描述）和程序流程图！

Answer 1

#include <stdio.h>
#include <string.h>
#include <malloc.h>
#define MaxSize 100
typedef char ElemType;
#define N 50        //叶子结点数
#define M 2*N-1     //树中结点总数

//哈夫曼树的节点结构类型
typedef struct
{
    char data;  //结点值
    double weight;  //权重
    int parent;     //双亲结点
    int lchild;     //左孩子结点
    int rchild;     //右孩子结点
} HTNode;

//每个节点哈夫曼编码的结构类型
typedef struct
{
    char cd[N]; //存放哈夫曼码
    int start;
} HCode;

void CreateHT(HTNode ht[],int n)
{
    int i,k,lnode,rnode;
    double min1,min2;
    for (i=0; i<2*n-1; i++)         //所有结点的相关域置初值-1
        ht[i].parent=ht[i].lchild=ht[i].rchild=-1;
    for (i=n; i<2*n-1; i++)         //构造哈夫曼树
    {
        min1=min2=32767;            //lnode和rnode为最小权重的两个结点位置
        lnode=rnode=-1;
        for (k=0; k<=i-1; k++)
            if (ht[k].parent==-1)   //只在尚未构造二叉树的结点中查找
            {
                if (ht[k].weight<min1)
                {
                    min2=min1;
                    rnode=lnode;
                    min1=ht[k].weight;
                    lnode=k;
                }
                else if (ht[k].weight<min2)
                {
                    min2=ht[k].weight;
                    rnode=k;
                }
            }
        ht[i].weight=ht[lnode].weight+ht[rnode].weight;
        ht[i].lchild=lnode;
        ht[i].rchild=rnode;
        ht[lnode].parent=i;
        ht[rnode].parent=i;
    }
}

//实现哈夫曼编码
void CreateHCode(HTNode ht[],HCode hcd[],int n)
{
    int i,f,c;
    HCode hc;
    for (i=0; i<n; i++) //根据哈夫曼树求哈夫曼编码
    {
        hc.start=n;
        c=i;
        f=ht[i].parent;
        while (f!=-1)   //循序直到树根结点
        {
            if (ht[f].lchild==c)    //处理左孩子结点
                hc.cd[hc.start--]='0';
            else                    //处理右孩子结点
                hc.cd[hc.start--]='1';
            c=f;
            f=ht[f].parent;
        }
        hc.start++;     //start指向哈夫曼编码最开始字符
        hcd[i]=hc;
    }
}

//输出哈夫曼编码
void DispHCode(HTNode ht[],HCode hcd[],int n)
{
    int i,k;
    double sum=0,m=0;
    int j;
    printf("  输出哈夫曼编码:\n"); //输出哈夫曼编码
    for (i=0; i<n; i++)
    {
        j=0;
        printf("      %c:\t",ht[i].data);
        for (k=hcd[i].start; k<=n; k++)
        {
            printf("%c",hcd[i].cd[k]);
            j++;
        }
        m+=ht[i].weight;
        sum+=ht[i].weight*j;
        printf("\n");
    }
    printf("\n  平均长度=%g\n",1.0*sum/m);
}

int main()
{
    int n=8,i;      //n表示初始字符串的个数
    char str[]= {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'};
    double fnum[]= {0.07,0.19,0.02,0.06,0.32,0.03,0.21,0.1};
    HTNode ht[M];
    HCode hcd[N];
    for (i=0; i<n; i++)
    {
        ht[i].data=str[i];
        ht[i].weight=fnum[i];
    }
    printf("\n");
    CreateHT(ht,n);
    CreateHCode(ht,hcd,n);
    DispHCode(ht,hcd,n);
    printf("\n");}