/*
*Copyright (c) 2014,烟台大学计算机学院
*All rights reserved.
*文件名称:Annpion.cpp
*作者:王耀鹏
*完成日期:2016年1月9日
*版本号:v1.0
*
*问题描述:哈夫曼编码
*输入描述:无
*输出描述:输出哈夫曼编码
*/
#include<stdio.h>
#include<string.h>
#define N 50
typedef struct
{
char data;
double weight;
int parent;
int lchild;
int rchild;
}HTNode;
typedef struct
{
char cd[N];
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)
ht[i].parent=ht[i].lchild=ht[i].rchild=-1;
for(i=n;i<2*n-1;++i)
{
min1=min2=32767;
lnode=rnode=-1;
for(k=0;k<i;++k)
{
if(ht[k].parent==-1)
{
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[lnode].parent=i;
ht[rnode].parent=i;
ht[i].weight=ht[lnode].weight+ht[rnode].weight;
ht[i].lchild=lnode;
ht[i].rchild=rnode;
}
}
void CreateHCode(HTNode ht[],HCode hcd[],int n)
{
int i,f,c;
HCode hc;
for(i=0;i<n;++i)
{
hc.start=n;
c=i;
f=ht[i].parent;
while(f!=-1)
{
if(ht[f].lchild==c)
hc.cd[hc.start--]='0';
else
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;
}
}
void DispHCode(HTNode ht[],HCode hcd[],int n)
{
int i,j,k;
double sum=0,m=0;
printf(" 输出哈夫曼编码:\n");
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[2*N-1];
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");
return 0;
}
运行结果：
