标题:
C语言经典算法之哈慢树
[打印本页]
作者:
苹果也疯狂
时间:
2014-5-22 09:47
标题:
C语言经典算法之哈慢树
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#define n 6
#define m 2*n-1
typedef struct
{ float weight;
intlchild,rchild,parent;
}codenode;
typedef codenode huffmantree[m];
typedef struct
{ char ch;
charbits[n+1];
}code;
typedef code huffmancode[n];
void inithf(huffmantree T) //
-哈夫曼树的初始化
{ int i;
for(i=0;i<m;i++)
{T
.weight=0;
T
.parent=-1;
T
.lchild=-1;
T
.rchild=-1;
}
}
void inputhf(huffmantree T) //
-输入哈夫曼树的树据
{ int i;float k;
for(i=0;i<n;i++)
{scanf("%f",&k);
T
.weight=k;
}
}
void selectmin(huffmantree T,int k,int*p1,int *p2)
{ int i;float small1=10000,small2=10000;
for(i=0;i<=k;i++)
{if(T
.parent==-1)
if(T
.weight<small1)
{small2=small1;
small1=T
.weight;
*p2=*p1;
*p1=i;
}
else
if(T
.weight<small2)
{ small2=T
.weight;
*p2=i;
}
}
}
void creathftree(huffmantree T) //
-建哈夫曼树
{ int i,p1,p2;
inithf(T);
inputhf(T);
for(i=n;i<m;i++)
{selectmin(T,i-1,&p1,&p2);
T[p1].parent=T[p2].parent=i;
T
.lchild=p1;
T
.rchild=p2;
T
.weight=T[p1].weight+T[p2].weight;
}
}
void creathfcode(huffmantree T, huffmancodeH) //
-哈夫曼编码表
{ int i,c,p,start;char cd[n+1];
cd[n]='\0';
for(i=0;i<n;i++)
{H
.ch=getchar();
start=n;
c=i;
while((p=T[c].parent)>=0)
{
cd[--start]=(T[p].lchild==c)?'0':'1';
c=p;
}
strcpy(H
.bits,&cd[start]);
}
}
void zip(huffmancode H,char *ch,char*s) //
-编码
{ int j=0;char *p[n]; unsigned int i;
for(i=0;i<strlen(ch);i++)
{ while(ch
!=H[j].ch) j++;
p
=H[j].bits;
}
strcpy(s,p[0]);
for(i=1;i<n;i++)
strcat(s,p
);
puts(s);
}
void uzip(huffmancode H,char *s,huffmantreeT) //
-解码
{ int j=0,p;
unsigned int i;
charch[n+1];
while(i<strlen(s))
{p=m-1;
while(T[p].lchild!=-1)
{ if(s[ i ]=='0')
{p=T[p].lchild;i++;}
else
{p=T[p].rchild;i++;}
}
ch[j]=H[p].ch;
j++;
}
ch[j]='\0';
puts(ch);
}
main()
{ char ch[]="abcdef", s[36];
huffmantree T;
huffmancode H;
creathftree(T);
getchar();
creathfcode(T,H);
zip(H,ch,s);
uzip(H,s,T);
}
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