哈夫曼树编码与译码解码运用

#include<stdio.h>
#include<conio.h>
#define MAXVALUE 10000
#define MAXLEAF 30
#define MAXNODE MAXLEAF*2-1
#define MAXBIT 50
typedef struct node{
char letter;
int weight;
int parent;
int lchild;
int rchild;
}HNodeType;
typedef struct {
char letter;
int bit[MAXBIT];
int start;
}HCodeType;
typedef struct {
char s;
int num;
}Bowen;
/*哈夫曼树的构造算法*/
void HuffmanTree(HNodeType HuffNode[],int n,Bowen a[])
{
int i,j,m1,m2,x1,x2,temp1;char temp2;
for(i=0;i<2*n-1;i++)
{
HuffNode[i].letter=NULL;
HuffNode[i].weight=0;
HuffNode[i].parent=-1;
HuffNode[i].lchild=-1;
HuffNode[i].rchild=-1;
}
for(i=0;i<n-1;i++)
for(j=i+1;j<n-1;j++)
if(a[j].num>a[i].num)
{
temp1=a[i].num;a[i].num=a[j].num;a[j].num=temp1;
temp2=a[i].s;a[i].s=a[j].s;a[j].s=temp2;}
for(i=0;i<n;i++)
{
HuffNode[i].weight=a[i].num;
HuffNode[i].letter=a[i].s;}
for(i=0;i<n-1;i++)   /*构造哈夫曼树*/
{
m1=m2=MAXVALUE;
x1=x2=0;
for(j=0;j<n+i;j++)  /*找出的两棵权值最小的子树*/
{
if(HuffNode[j].parent==-1&&HuffNode[j].weight<m1)
{
m2=m1;x2=x1;
m1=HuffNode[j].weight;  x1=j;
}
else if(HuffNode[j].parent==-1&&HuffNode[j].weight<m2)
{
m2=HuffNode[j].weight;
x2=j;
}
}
/*将找出的两棵子树合并为一棵子树*/
HuffNode[x1].parent=n+i;HuffNode[x2].parent=n+i;
HuffNode[n+i].weight=HuffNode[x1].weight+HuffNode[x2].weight;
HuffNode[n+i].lchild=x1; HuffNode[n+i].rchild=x2;
}
}
/*生成哈夫曼编码*/
void HuffmanCode(int n,Bowen a[])
{
HNodeType HuffNode[MAXNODE];
HCodeType HuffCode[MAXLEAF],cd;
int i,j,c,p;
char code[30],*m;
HuffmanTree(HuffNode,n,a); /*建立哈夫曼树*/
for(i=0;i<n;i++)            /*求每个叶子结点的哈夫曼编码*/
{
cd.start=n-1;
c=i;
p=HuffNode[c].parent;
while(p!=-1)           /*由叶结点向上直到树根*/
{
if(HuffNode[p].lchild==c)
cd.bit[cd.start]=0;
else
cd.bit[cd.start]=1;
cd.start--;
c=p;
p=HuffNode[c].parent;}
for(j=cd.start+1;j<n;j++) /*保存求出的每个叶结点的哈夫曼编码和编码的起始位*/
HuffCode[i].bit[j]=cd.bit[j];
HuffCode[i].start=cd.start;
}
printf("输出每个叶子的哈夫曼编码：\n");
for(i=0;i<n;i++)   /*输出每个叶子结点的哈夫曼编码*/
{
HuffCode[i].letter=HuffNode[i].letter;
printf(" %c:",HuffCode[i].letter);
for(j=HuffCode[i].start+1;j<n;j++)
printf(" %d",HuffCode[i].bit[j]);
printf("\n");
}
printf("请输入电文(1/0):\n");
for(i=0;i<30;i++) code[i]=NULL;
scanf(" %s",&code);   m=code;
c=2*n-2;
printf("输出哈夫曼译码:\n");
while(*m!=NULL)
{
if(*m=='0')
{
c=i=HuffNode[c].lchild;
if(HuffNode[c].lchild==-1&&HuffNode[c].rchild==-1)
{
printf("%c",HuffNode[i].letter);
c=2*n-2;
}
}

if(*m=='1')
{
c=i=HuffNode[c].rchild;
if(HuffNode[c].lchild==-1&&HuffNode[c].rchild==-1)
{
printf("%c",HuffNode[i].letter);c=2*n-2;
}
}
m++;
}
printf("\n");
}
int main(void)
{
Bowen data[30];
char s[100],*p;
int i,count=0;
printf("\n 请输入一些字符:");
scanf("%s",&s);
for(i=0;i<30;i++)
{
data[i].s=NULL;
data[i].num=0;}
p=s;
while(*p)
{
for(i=0;i<=count+1;i++)
{
if(data[i].s==NULL)
{
data[i].s=*p;data[i].num++;count++;break;
}
else if(data[i].s==*p)
{
data[i].num++;break;
}
}
p++;
}
printf("\n");
printf(" 不同的字符数:%d\n",count);
for(i=0;i<count;i++)
{
printf(" %c ",data[i].s);
printf(" 权值:%d",data[i].num);
printf("\n");
}
HuffmanCode(count,data);
getch();
}