c語言實現哈夫曼編碼
#include <stdio.h>
#include <math.h>
#define MAX 100
#define MAXSYMBS 30
#define MAXNODE 59
#define DEEP 10
typedef struct{
float weight;
int flag;
int parent;
int lchilde;
int rchilde;
}huffnode;
/*哈夫曼樹結構定義*/
typedef struct{
int bits[MAXSYMBS];
int start;
}huffcode;
int main(void)
{
huffnode huff_node[MAXNODE];
huffcode huff_code[MAXSYMBS],cd;
int i,j,x1,x2,n,c,p;
float m1,m2,temp,hx=0,KL=0;
clrscr();
printf("Please input the leaf num of tree:/n");
scanf("%d",&n);
for(i=0;i<=2*n-1;i++)
{
huff_node[i].weight=0;
huff_node[i].parent=0;
huff_node[i].flag=0;
huff_node[i].lchilde=-1;
huff_node[i].rchilde=-1;
}
printf("Please input the weight of every leaf/n");
for(i=0;i<n;i++)
{ printf("input %dth weight>>",i+1);
scanf("%f",&temp);
huff_node[i].weight=temp;
hx=hx-temp*3.332*log10(temp);
}
/*構建哈夫曼樹*/
for(i=0;i<n-1;i++)
{
m1=m2=MAX;
x1=x2=0;
for(j=0;j<n+i;j++)
{
if(huff_node[j].weight<m1&&huff_node[j].flag==0)
{
m2=m1;
x2=x1;
m1=huff_node[j].weight;
x1=j;
}
else
if(huff_node[j].weight<m2&&huff_node[j].flag==0)
{
m2=huff_node[j].weight;
x2=j;
}
}
huff_node[x1].parent=n+i;
huff_node[x2].parent=n+i; /*將找出的兩棵子樹合併為一棵子樹*/
huff_node[x1].flag=1;
huff_node[x2].flag=1;
huff_node[n+i].weight=huff_node[x1].weight+huff_node[x2].weight;
huff_node[n+i].lchilde=x1;
huff_node[n+i].rchilde=x2;
}
/*求字元的哈夫曼編碼*/
for(i=0;i<n;i++)
{
cd.start=n;
c=i;
p=huff_node[c].parent;
while(p!=0)
{
if(huff_node[p].lchilde==c) cd.bits[cd.start]=0;
else cd.bits[cd.start]=1;
cd.start=cd.start-1;
c=p;
p=huff_node[p].parent;
}
cd.start++;
for(j=cd.start;j<=n;j++)
{
huff_code[i].bits[j]=cd.bits[j];
huff_code[i].start=cd.start;
}
}
/*輸出字元的編碼*/
printf("/nweight/thuffmancode/n");
for(i=0;i<n;i++)
{
printf("%2.3f:/t",huff_node[i].weight);
for(j=huff_code[i].start;j<=n;j++)
printf("%d",huff_code[i].bits[j]);
KL=KL+(n-huff_code[i].start+1)*huff_node[i].weight;
printf("/n");
}
printf("/nH(X)=%f/tKL=%f/nR=%f",hx,KL,hx/KL);
return 0;
}