u1、能够对27个字符进行编码、并存储.
2、利用编码能够实现任意英文句子的编码操作，并存储编码。
3、能够将二进制的密码翻译成句子，并将译文存储。
4、能随时查看字母的编码.
要求是相同的,不相同的地方就是涉及输入的地方,这个相信你可以自己解决的吧,
#include<stdlib.h>
#include<stdio.h>
#include<string.h>
#include<conio.h>
typedef struct
{
int weight;
int parent;
int left;
int right;
}hfmt;
typedef char*hfmcode;
void selectnode(hfmt *ht,int n,int *bt1,int *bt2)
{
int i;
hfmt *ht1,*ht2,*t;
ht1=ht2=NULL;
for(i=1;i<n+1;i++)
{
if(!ht[i].parent)
{
if(ht1==NULL)
{
ht1=ht+i;
continue;
}
if(ht2==NULL)
{
ht2=ht+i;
if(ht1->weight>ht2->weight)
{
t=ht2;
ht2=ht1;
ht1=t;
}
continue;
}
if(ht1&&ht2)
{
if(ht[i].weight<=ht1->weight)
{
ht2=ht1;
ht1=ht+i;
}
else if (ht[i].weight>ht1->weight)
{
ht2=ht+i;
}
}
}
}
if(ht1>ht2){
*bt2=ht1-ht;
*bt1=ht2-ht;
}
else{
*bt1=ht1-ht;
*bt2=ht2-ht;
}
}
void createtree(hfmt *ht,int n,int *w)
{
int i,m=2*n-1,bt1,bt2;
if(n<=1)return;
for(i=1;i<=n;++i)
{
ht[i].weight=w[i-1];
ht[i].parent=0;
ht[i].left=0;
ht[i].right=0;
}
for(;i<=m;i++)
{
ht[i].weight=0;
ht[i].parent=0;
ht[i].left=0;
ht[i].right=0;
}
for(i=n+1;i<=m;i++)
{
selectnode(ht,i-1,&bt1,&bt2);
ht[bt1].parent=i;
ht[bt2].parent=i;
ht[i].left=bt1;
ht[i].right=bt2;
ht[i].weight=ht[bt1].weight=ht[bt2].weight;
}
}
void hfmcoding(hfmt *ht,int n,hfmcode *hc)
{
char*cd;
int start ,i;
int current,parent;
cd=(char*)malloc(sizeof(char)*n);
cd[n-1]='\0';
for(i=1;i<=n;i++)
{
start=n-1;
current=i;
parent=ht[current].parent;
while(parent)
{
if(current==ht[parent].left)
cd[--start]='0';
else
cd[--start]='1';
current=parent;
parent=ht[parent].parent;
}
hc[i-1]=(char*)malloc(sizeof(char)*(n-start));
strcpy(hc[i-1],&cd[start]);
}
free(cd);
}
void insert(hfmcode *hc,char*alphabet,char*str,char*code)
{
int len=0,i=0,j;
code[0]='\0';
while(str[i])
{
j=0;
while(alphabet[j]!=str[i])
j++;
strcpy(code+len,hc[j]);
len=len+strlen(hc[j]);
i++;
}
code[len]='\0';
}
void delete_(hfmt*ht,int m,char*code,char*alphabet,char*decode)
{
int position=0,i,j=0;
m=2*m-1;
while(code[position])
{
for(i=m;ht[i].left&&ht[i].right;position++)
{
if(code[position]=='0')
i=ht[i].left;
else
i=ht[i].right;
}
decode[j]=alphabet[i-1];
j++;
}
decode[j]='\0';
}
int main()
{
int i,n=4,m;
char test[]="DBDABCDABBCDBADCBDBCDBCDAB";
char code[100],code1[100];
char alphabet[]={'A','B','C','D'};
int w[]={4,9,5,8};
hfmt *ht;
hfmcode *hc;
m=2*n-1;
ht=(hfmt*)malloc((m+1)*sizeof(hfmt));
if(!ht)
{
printf("内存分配失败\n");
exit(0);
}
hc=(hfmcode*)malloc(n*sizeof(char*));
if(!hc)
{
printf("内存分配失败\n");
exit(0);
}
createtree(ht,n,w);
hfmcoding(ht,n,hc);
for(i=1;i<=n;i++)
printf("字母:%c,权重:%d,编码为 %s\n",alphabet[i-1],ht[i].weight,hc[i-1]);
insert(hc,alphabet,test,code);
printf("\n字符串:\n%s\n转换后为:\n%s\n",test,code);
delete_(ht,n,code,alphabet,code1);
printf("\n编码:\n%s\n转换后为:\n%s\n",code,code1);
getch();
return 0;
}
