哈夫曼译码
1000(ms)
10000(kb)
1974 / 4142
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
#include<iostream>
#include<stdio.h>
#include<stdlib.h>
using namespace std;
const int maxvalue=100;
const int maxbit=100;
const int maxn=100;
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[])//树的生成
{
int j,m1,m2,x1,x2,i;
for(i=0;i< 2*n-1;i++)//初始化哈夫曼树
{
if(i < n)//将0到n-1依次储存相应的权重和数字
{
hafftree[i].weight=weight[i];
hafftree[i].ch=text[i];
}
else//将到2n-2依次设置权重为0，字符为#
{
hafftree[i].weight=0;
hafftree[i].ch='#';
}
hafftree[i].parent=0;//初始化双亲结点
hafftree[i].flag=0;//初始化标记
hafftree[i].leftchild=-1;//初始化左孩子
hafftree[i].rightchild=-1;//初始化右孩子
}
for(i=0;i< n-1;i++)
{
m1=m2=maxvalue;
x1=x2=0;
for(j=0;j< n+i;j++)//循环找出未最小权重的2个结点，x1储存最小结点的序号，x2储存第2小结点的序号，m1储存最小结点的权重，m2储存第2小结点的权重
{
if(hafftree[j].weight< m1&&hafftree[j].flag==0)//如果该结点的权重小于m1，并且未标记使用过，则将其权重以及序号赋值给m1，x1，原x1变x2，原m1变m2
{
m2=m1;
x2=x1;
m1=hafftree[j].weight;
x1=j;
}
else if(hafftree[j].weight< m2&&hafftree[j].flag==0)//如果该结点的权重小于m2，并且未标记使用过，则将其权重以及序号赋值给m2，x2
m2=hafftree[j].weight;
x2=j;
}
}
hafftree[x1].parent=n+i;//最小结点的双亲赋值
hafftree[x2].parent=n+i;//第2小结点的双亲赋值
hafftree[x1].flag=1; //标记最小以及第二小结点为已经使用过
hafftree[x2].flag=1;
hafftree[n+i].weight=hafftree[x1].weight+hafftree[x2].weight;//该结点为刚刚找到的最小结点以及第二小结点的双亲，其权重为左右孩子权重的和
hafftree[n+i].leftchild=x1;
hafftree[n+i].rightchild=x2;
}
}
void haffmancode(haffnode hafftree[],int n,code haffcode[])//编码 忽略！
{
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)//翻译解码
{
char data[100];
int t=2*n-2;//t为树根结点的序号
scanf("%s",data);//输入需要翻译的字符串
for(int i=0;data[i]!='\n';i++)
{
if(data[i]=='0') t=hafftree[t].leftchild;//如果为0，则向左孩子搜索
else if(data[i]=='1') t=hafftree[t].rightchild;//如果为1，则向右孩子搜索
if(hafftree[t].leftchild==-1)//如果左孩子为-1，则表示已经到了树的底部，则输出其对应的字符，然后重新从根结点继续寻找下一个字符
{
printf("%c",hafftree[t].ch);
t=2*n-2;
}
}
}
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;
}