哈夫曼编码的设计

给定若干权值，建立哈夫曼树，并进行编码，将编码输出。给出一段明文，设计程序将明文经过编码形成密文，再设计程序将密文翻译成明文

#include<stdio.h>
#include<conio.h>
#define MAXVALUE 10000
#define MAXLEAF 30
#define MAXNODE MAXLEAF*2-1
#define MAXBIT 50
#define NULL 0
typedef struct node{
	char letter;
	    int weight;
		int parent;
		int lchild;
		int rchild;
}HNodeType;
typedef struct {
	char letter;
	   int bit[MAXBIT];
	   int start;
}HCodeType;
typedef struct{
	char s;
	     int num;
}Message;
void HuffmanTree(HNodeType HuffNode[],int n,Message a[])
{
	int i,j,m1,m2,x1,x2,temp1;char temp2;
	for(i=0;i<2*n-1;i++)
	{
		HuffNode[i].letter=NULL;
		HuffNode[i].weight=0;
		HuffNode[i].parent=-1;
		HuffNode[i].lchild=-1;
		HuffNode[i].rchild=-1;
	}
	for(i=0;i<n-1;i++)
		for(j=i+1;j<n-1;j++)
			if(a[j].num>a[i].num)
			{
				temp1=a[i].num;a[i].num=a[j].num;a[j].num=temp1;
				temp2=a[i].s;a[i].s=a[j].s;a[j].s=temp2;
			}
			for(i=0;i<n;i++)
			{
				HuffNode[i].weight=a[i].num;
				HuffNode[i].letter=a[i].s;
			}
			for(i=0;i<n-1;i++)
			{
				m1=m2=MAXVALUE;
				x1=x2=0;
				for(j=0;j<n+1;j++)
				{
					if(HuffNode[j].parent==-1&&HuffNode[j].weight<m1)
					{
						m2=m1;x2=x1;
						m1=HuffNode[j].weight;   x1=j;
					}
					else if(HuffNode[j].parent==-1&&HuffNode[j].weight<m2)
					{
						m2=HuffNode[j].weight;
						x2=j;
					}
				}
				HuffNode[x1].parent=n+1;HuffNode[x2].parent=n+1;
				HuffNode[n+i].weight=HuffNode[x1].weight+HuffNode[x2].weight;
				HuffNode[n+i].lchild=x1;HuffNode[n+i].rchild=x2;
			}
}
void HuffmanCode(int n,Message a[])
{
	HNodeType HuffNode[MAXNODE];
	HCodeType HuffCode[MAXLEAF],cd;
	int i,j,c,p;
	char code[30],*m;
	HuffmanTree(HuffNode,n,a);
	for(i=0;i<n;i++)
	{
		cd.start=n-1;
		c=i;
		p=HuffNode[c].parent;
		while(p!=-1)
		{
			if(HuffNode[p].lchild==c)
				cd.bit[cd.start]=0;
			else
				cd.bit[cd.start]=1;
			cd.start--;
			c=p;
			p=HuffNode[c].parent;
		}
		for(j=cd.start+1;j<n;j++)
			HuffCode[i].bit[j]=cd.bit[j];
		HuffCode[i].start=cd.start;
	}
	printf("输入每个叶子的哈夫曼编码: \n");
	for(i=0;j<n;i++)
	{
		HuffCode[i].letter=HuffNode[i].letter;
		printf(" %c:",HuffCode[i].letter);
		for(j=HuffCode[i].start+1;j<n;j++)
			printf("%d",HuffCode[i].bit[j]);
		    printf("\n");
	}
	printf("请输入电文(1/0):\n");
	for(i=0;i<30;i++)code[i]=NULL;
	scanf(" %s",&code);  m=code;
	c=2*n-2;
	printf("输出哈夫曼译码:\n");
	while(*m!=NULL)
	{
		if(*m=='0')
		{
			c=i=HuffNode[c].lchild;
			if(HuffNode[c].lchild==-1&&HuffNode[c].rchild==-1)
			{
				printf("%c",HuffNode[i].letter);
				c=2*n-2;
			}
		}
		if(*m=='1')
		{
			c=i=HuffNode[c].rchild;
			if(HuffNode[c].lchild==-1&&HuffNode[c].rchild==-1)
			{
				printf("%c",HuffNode[i].letter);
				c=2*n-2;
			}
		}
		m++;
	}
	printf("\n");
}
void main()
{
	Message data[30];
	char s[100],*p;
	int i,count=0;
	printf("\n 请输入一些字符:");
	scanf("%s",&s);
	for(i=0;i<30;i++)
	{
		data[i].s=NULL;
		data[i].num=0;
	}
	p=s;
	while(*p)
	{
		for(i=0;i<=count+1;i++)
		{
			if(data[i].s==NULL)
			{
				data[i].s=*p;data[i].num++;count++;break;
			}
			else if(data[i].s==*p)
			{
				data[i].num++;break;
			}
		}
		p++;
	}
	printf("\n");
	printf("不同的字符数:%d\n",count);
	for(i=0;i<count;i++)
	{
		printf(" %c",data[i].s);
		printf(" 权值 :%d",data[i].num );
		printf("\n");
	}
	HuffmanCode(count,data);
	getch();
}