Huffman树的利用：
1、先选择1篇文章
2、然后统计字符个数
3、对个数不为0字符的进行编码
4、输出码文
5、进行译码
上机代码：
/*************************************************************************
> File Name: Huffman树的利用.cpp
> Author: zzuspy
> Mail: zzuspy@qq.com
> Created Time: 2014年12月3日 14:30
************************************************************************/
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <cmath>
#include <stack>
#include <queue>
#define LL long long
#define max3(a,b,c) max(a,max(b,c))
#define min3(a,b,c) min(a,min(b,c))
using namespace std;
typedef struct
{
int weight;
int parent, lchild, rchild;
}HTNode, *HuffmanTree;
typedef char * * HuffmanCode;
int s1, s2;
void Select(HuffmanTree &HT, int n)
{
int i, min;
for(int i=1; i<=n; i++)
{
if(HT[i].parent==0)
{
min = i;
break;
}
}
for(i=1; i<=n; i++)
{
if(HT[i].weight<HT[min].weight && HT[i].parent == 0)min = i;
}
s1 = min;
for(int i=1; i<=n; i++)
{
if(HT[i].parent==0 && i!=s1)
{
min = i;
break;
}
}
for(int i=1; i<=n; i++)
{
if(HT[i].parent == 0 && i!=s1 && HT[i].weight<HT[min].weight && HT[i].weight>=HT[s1].weight) min=i;
}
s2 = min;
}
void HuffmanCoding(HuffmanTree &HT, HuffmanCode &HC, int *w, int n)
{
if(n<=1) return;
int m = 2 * n - 1, i;
HuffmanTree p;
HT = (HuffmanTree)malloc( (m + 1) * sizeof(HTNode));
for( p = HT+1, i = 1; i <= n; i++, p++, w++)
{
p->weight = *w;
p->parent = p->lchild = p->rchild = 0;
}
for(; i <= m; i++, p++)
{
p->weight = p->parent = p->lchild = p->rchild = 0;
}
//输出这时候Huffman树
/*for(int i=1; i<=n; i++)
{
printf("%d %d %d %d
", HT[i].weight, HT[i].parent, HT[i].lchild, HT[i].rchild);
}*/
for(i = n + 1; i<=m; i++)
{
Select(HT, i⑴);
//printf("%d %d
", s1, s2);
HT[s1].parent = i; HT[s2].parent = i;
HT[i].lchild = s1; HT[i].rchild = s2;
HT[i].weight = HT[s1].weight + HT[s2].weight;
}
HC = (HuffmanCode)malloc( ( n + 1 ) * sizeof(char *));
char *cd = (char *)malloc( n * sizeof(char) );
cd[n⑴] = ' ';
for(i=1; i<=n; i++)
{
int start = n - 1;
for(int c = i, f = HT[i].parent; f!=0; c=f, f=HT[f].parent)
if(HT[f].lchild == c) cd[--start] = '0';
else cd[--start] = '1';
HC[i] = (char*)malloc( (n-start) * sizeof(char));
strcpy(HC[i], &cd[start]);
}
free(cd);
}
void mawen(HuffmanCode &HC, char str[])
{
printf("
");
FILE *p;
char c;
p = fopen("essay","r");
while((c = fgetc(p))!=EOF)
{
for(int i=0; str[i]!=' '; i++)
{
if(str[i] == c)
{
printf("%c %s ", c, HC[i+1]);
break;
}
}
}
fclose(p);
printf("
");
}
void codetext(char wen[], HuffmanCode &HC, char str[])
{
int start = 0;
FILE *p;
char c;
p = fopen("essay","r");
while((c = fgetc(p))!=EOF)
{
for(int i=0; str[i]!=' '; i++)
{
if(str[i] == c)
{
strcpy(wen+start, HC[i+1]);
start+=strlen(HC[i+1]);
break;
}
}
}
fclose(p);
printf("
");
}
void translate(char wen[], int wei[], char str[], HuffmanTree &HT, HuffmanCode &HC, int elem)
{
int q = 2 * elem - 1, n=0;
char *ch;
ch = (char*)malloc(100*sizeof(char));
for(int i=0; wen[i]!=' '; i++)
{
if(wen[i] == '0')
{
*(ch+n) = '0';
*(ch+n+1) = ' ';
n++;
q = HT[q].lchild;
if(HT[q].rchild==0 && HT[q].lchild==0)
{
int i;
for(i=0; i<elem; i++)
{
if(!strcmp(ch, HC[i+1]))break;
}
printf("%c", str[i]);
q = 2 * elem - 1;
n = 0;
}
}
else if(wen[i] == '1')
{
*(ch+n) = '1';
*(ch+n+1) = ' ';
n++;
q = HT[q].rchild;
if(HT[q].rchild==0 && HT[q].lchild==0)
{
int i;
for(i=0; i<elem; i++)
{
if(!strcmp(ch, HC[i+1]))break;
}
printf("%c", str[i]);
q = 2 * elem - 1;
n = 0;
}
}
}
}
int wei[128]; //保存字符数大于0的每一个字符的数目 (即权值)
char str[128]; //保存字符数大于0的字符
int elem = 0; //统计后字符数大于0的字符的总数
int statis[128]; //统计文章中各种字符的数目
char wen[1000010]; //用于保存码文
int main()
{
//打开文件读取字符，再统计每一个字符的个数
FILE *p;
char c;
p = fopen("essay","r");
while((c = fgetc(p))!=EOF)
{
printf("%c", c); //输出文章
statis[c]++;
}
fclose(p);
//输出统计后个数大于0的字符
/*for(int i=0; i<128; i++)
{
if(statis[i]!=0)
printf("%c : %d ", i, statis[i]);
}*/
//紧缩字符，去掉字符数为0的字符
for(int i=0; i<128; i++)
{
if(statis[i]!=0)
{
str[elem] = i;
wei[elem] = statis[i];
elem++;
}
}
//输出紧缩后字符及其个数
/*for(int i=0; i<elem; i++)
{
printf("%c : %d ", str[i], wei[i]);
}*/
//printf("
%d
", elem); //个数大于0的字符总数
HuffmanTree HT;
HuffmanCode HC;
//调用Huffman函数 ，将每一个字符对应的编码存在HC里，HT为你所建立的Huffman树
HuffmanCoding(HT, HC, wei, elem);
//输出构造的Huffman树
/*for(int i=1; i<=2*elem⑴; i++)
{
printf("%d %d %d %d %d
", i, HT[i].weight, HT[i].parent, HT[i].lchild, HT[i].rchild);
}*/
//输出个数大于0的字符及其字符编码
/*for(int i=1; i<=elem; i++)
{
printf("
%c %s
", str[i⑴], HC[i]);
}*/
printf("
");
//调用码文函数
mawen(HC, str);
printf("
");
//生成码文
codetext(wen, HC, str);
//printf("%s
", wen);
//译文
translate(wen, wei, str, HT, HC, elem);
return 0;
}