赫夫曼树的实现

////////////// 主要操作的是下标
#if 1
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include<windows.h>
#define Max 32767
typedef char* HuffMan;
typedef struct Node
{
    int weight; 
    int parent; 
	int	lchild,rchild;
}htnode,*HuffManTree;
void Select(HuffManTree *HT,int n,int *s1,int *s2)   
{
    int i;
    int min_weight=Max;
	if(n<1)
	{
		printf("n的范围不对！结束");
		exit(-1);
	}
    for(i=1;i<=n;i++)     
    {
        if((*HT)[i].parent==0)
        {
            if((*HT)[i].weight<min_weight)
            {
                min_weight=(*HT)[i].weight;
                *s1=i;
            }
        }
    }
    (*HT)[*s1].parent=1;  //标记s1已经被查询过
    min_weight=Max;
    for(i=1;i<=n;i++)    
    {
        if((*HT)[i].parent==0)
        {
            if((*HT)[i].weight<min_weight)
            {
                min_weight=(*HT)[i].weight;
                *s2=i;
            }
        }
    }
    (*HT)[*s2].parent=1; //标记s2已经被查询过
}
void HuffManCoding(HuffManTree *HT,int *w,int n) 
{ 
    int i;
	int s1,s2;
    int m=2*n-1;
    *HT=(HuffManTree)malloc((m+1)*sizeof(htnode));
    if(NULL==HT)
	{
		printf("开辟空间失败");
		exit(-1);
	}
    for(i=1;i<=n;i++)
    {
        (*HT)[i].weight=*w;
        (*HT)[i].parent=0;
        (*HT)[i].lchild=0;
        (*HT)[i].rchild=0;
		w++;
    }
    for(i=n+1;i<=m;i++)
    {
        (*HT)[i].weight=0;
        (*HT)[i].parent=0;
        (*HT)[i].lchild=0;
        (*HT)[i].rchild=0;
    }
    for(i=n+1;i<=m;i++)
    {
        Select(HT,i-1,&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;
    }
}
void HuffManInput(HuffManTree *HT,HuffMan* HC,int n) 
{
	int start;
	int c,f,i;
	char* cd=(char*)malloc(n*sizeof(char));
	if(NULL==cd)  exit(-1);
	HC=(HuffMan*)malloc((n+1)*sizeof(char*));
	if(NULL==HC)  exit(-1);
	cd[n-1]='\0';
	for(i=1;i<=n;i++)
	{
		start=n-1;
		f=(*HT)[i].parent;
		for(c=i;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));
		if(NULL==HC[i]) exit(-1);
		strcpy(HC[i],&cd[start]);
	}
	free(cd);
	printf("输出赫夫曼编码\n");
    for(i=1;i<=n;i++)
	{
		printf("%d：%s\n",(*HT)[i].weight,HC[i]);
	}
}
void main()
{
	int i=0;
    int number=0;
    int *w=NULL;
    HuffManTree HT=NULL;
    HuffMan HC=NULL;
    printf("请输入待编码字符的个数：\n");
    scanf("%d",&number);
    w=(int *)malloc(number*sizeof(int));
    if(!w) exit(-1);
    printf("请输入整形待权值\n");
    for(i=0;i<number;i++)
	{
		scanf("%d",&w[i]);
	}
    HuffManCoding(&HT,w,number);
	HuffManInput(&HT,&HC,number);
/*  for(i=1;i<=n;i++)
	{
		printf("%s\n",HC[i]);
	}*/
	system("pause");
	system("cls");
}
#endif