swust oj 986

哈夫曼译码

1000(ms)

10000(kb)

1997 / 4186

通常要求根据给定的编码本对密文进行解码。现已给定相应字符的哈夫曼编码，要求根据编码对密文进行解码。（建立哈夫曼树以及编码、主函数等都已经给出，你只需要填写译码函数void ccode(haffnode  hafftree[],int n)即可。

const int maxvalue=100;

const int maxbit=100;

const int maxn=100;

#include "iostream"

#include "stdio.h"

#include "stdlib.h"

using namespace std;

struct haffnode

{

char ch;

int weight;

int flag;

int parent;

int leftchild;

int rightchild;

};

struct code

{

int bit[maxn];

int start;

int weight;

char ch;

};

void haffman(int weight[],char text[],int n,haffnode hafftree[])

{

int j,m1,m2,x1,x2,i;

for(i=0;i< 2*n-1;i++)

{

if(i < n)

{

hafftree[i].weight=weight[i];

hafftree[i].

ch=text[i];

}

else

{

hafftree[i].weight=0;

hafftree[i].ch='#';

}

hafftree[i].parent=0;

hafftree[i].flag=0;

hafftree[i].leftchild=-1;

hafftree[i].rightchild=-1;

}

for(i=0;i< n-1;i++)

{

m1=m2=maxvalue;

x1=x2=0;

for(j=0;j< n+i;j++)

{

if(hafftree[j].weight< m1&&hafftree[j].flag==0)

{

m2=m1;

x2=x1;

m1=hafftree[j].weight;

x1=j;

}

else if(hafftree[j].weight< m2&&hafftree[j].flag==0)

{

m2=hafftree[j].weight; x2=j;

}

}

hafftree[x1].parent=n+i;

hafftree[x2].parent=n+i;

hafftree[x1].flag=1;

hafftree[x2].flag=1;

hafftree[n+i].weight=hafftree[x1].weight+hafftree[x2].weight;

hafftree[n+i].leftchild=x1; hafftree[n+i].rightchild=x2;

}

}

void haffmancode(haffnode hafftree[],int n,code haffcode[])

{

code cd; int i,j; int child,parent;

for( i=0;i< n;i++)

{

cd.start=n-1;

cd.weight=hafftree[i].weight;

cd.ch=hafftree[i].ch;

child=i;

parent=hafftree[child].parent;

while(parent!=0)

{

if(hafftree[parent].leftchild==child)

cd.bit[cd.start]=0;

else cd.bit[cd.start]=1;

cd.start--;

child=parent;

parent=hafftree[child].parent;

}

for(j=cd.start+1;j< n;j++)

haffcode[i].bit[j]=cd.bit[j];

haffcode[i].start=cd.start;

haffcode[i].weight=cd.weight;

haffcode[i].ch=cd.ch;

}

}

void ccode(haffnode hafftree[],int n)

{ }

int main( )

{

int n=8;

int weight[]={5,29,7,8,14,23,3,11};

char text[]={'a','b','c','d','e','f','g','h'};

haffnode myhafftree[maxvalue];

code myhaffcode[maxvalue];

haffman(weight,text,n,myhafftree);

haffmancode(myhafftree,n,myhaffcode);

ccode(myhafftree,n);

return 0;

}

输入

根据哈夫曼树编码表，针对字符串做好的编码结果。

输出

对每一行需要解码的串，进行解码，并输出解码后的结果。

样例输入

000100011011101110

样例输出

aabcc 

 const int maxvalue=;
 const int maxbit=;
 const int maxn=;
 #include "iostream"
 #include "stdio.h"
 #include "stdlib.h"
 #include "string.h"
 using namespace std;
 struct haffnode
 {
     char ch;
     int weight;
     int flag;
     int parent;
     int leftchild;
     int rightchild;
 };
 struct code
 {
     int bit[maxn];
     int start;
     int weight;
     char ch;
 };
 void haffman(int weight[],char text[],int n,haffnode hafftree[])
 {
     int j,m1,m2,x1,x2,i;
     for(i=; i< *n-; i++)
     {
         if(i < n)
         {
             hafftree[i].weight=weight[i];
             hafftree[i].
             ch=text[i];
         }
         else
         {
             hafftree[i].weight=;
             hafftree[i].ch='#';
         }
         hafftree[i].parent=;
         hafftree[i].flag=;
         hafftree[i].leftchild=-;
         hafftree[i].rightchild=-;
     }
     for(i=; i< n-; i++)
     {
         m1=m2=maxvalue;
         x1=x2=;
         for(j=; j< n+i; j++)
         {
             if(hafftree[j].weight< m1&&hafftree[j].flag==)
             {
                 m2=m1;
                 x2=x1;
                 m1=hafftree[j].weight;
                 x1=j;
             }
             else if(hafftree[j].weight< m2&&hafftree[j].flag==)
             {
                 m2=hafftree[j].weight;
                 x2=j;
             }
         }
         hafftree[x1].parent=n+i;
         hafftree[x2].parent=n+i;
         hafftree[x1].flag=;
         hafftree[x2].flag=;
         hafftree[n+i].weight=hafftree[x1].weight+hafftree[x2].weight;
         hafftree[n+i].leftchild=x1;
         hafftree[n+i].rightchild=x2;
     }
 }
 void haffmancode(haffnode hafftree[],int n,code haffcode[])
 {
     code cd;
     int i,j;
     int child,parent;
     for( i=; i< n; i++)
     {
         cd.start=n-;
         cd.weight=hafftree[i].weight;
         cd.ch=hafftree[i].ch;
         child=i;
         parent=hafftree[child].parent;
         while(parent!=)
         {
             if(hafftree[parent].leftchild==child)
                 cd.bit[cd.start]=;
             else
                 cd.bit[cd.start]=;
             cd.start--;
             child=parent;
             parent=hafftree[child].parent;
         }
         for(j=cd.start+; j< n; j++)
             haffcode[i].bit[j]=cd.bit[j];
         haffcode[i].start=cd.start;
         haffcode[i].weight=cd.weight;
         haffcode[i].ch=cd.ch;
     }
 }
 void ccode(haffnode hafftree[],int n)
 {
     int i,j=,m=*n-;
     char b[maxn];
     memset(b,'\0',sizeof(b));
     i=m-;
     scanf("%s",b);
     while(b[j]!='\0')
     {
         if(b[j]=='')
             i=hafftree[i].leftchild;
         else
             i=hafftree[i].rightchild;
         if(hafftree[i].leftchild==-)
         {
             printf("%c",hafftree[i].ch);
             i=m-;
         }
         j++;
     }
 }
 int main( )
 {
     int n=;
     int weight[]= {,,,,,,,};
     char text[]= {'a','b','c','d','e','f','g','h'};
     haffnode myhafftree[maxvalue];
     code myhaffcode[maxvalue];
     haffman(weight,text,n,myhafftree);
     haffmancode(myhafftree,n,myhaffcode);
     ccode(myhafftree,n);
     return ;
 }