c语言 哈夫曼编码

哈夫曼编码：字符种数or叶子数+1，结点数：算出来m=67，父结点数为2*67-1=133仅对此文档有效,2*maxsymbs-1。

#include 
#include 
#define maxsymbs 68               //字符种数or叶子数+1
#define maxnode 133              //结点数：算出来m=67，父结点数为2*67-1=133仅对此文档有效,2*maxsymbs-1


void rate();   //求字符在文章中出现的频率
void sort();   //排序
void huffmantree();//构造哈夫曼树
void table();            //建立码表
void huffmancode();      //哈夫曼编码
void code_txt();         //对文档编码
void decode_txt();	//解码

int n[127] = {0};                        //字符出现的次数
double symbrate[127] = {0};              //字符出现的频率
int num = 0;                             //字符总数
int m = 0;                               //字符种数or叶子数
int code_num = 0;                       //编码总数

struct huffnode
{
    int weight;   //权重
    int flag;	  //标志
    int parent;	   //父结点
    int lchild;	   //左孩子
    int rchild;    //右孩子
} huff_node[maxnode];
struct huffcode
{
    int bits[maxsymbs];
    int start;
} huff_code[maxsymbs], cd;

struct tab            //码表结构
{
    char ch;
    int ch_num;
} tab[maxsymbs];

int main()
{
    rate();
    sort();
    huffmantree();
    huffmancode();
    table();
    code_txt();
    decode_txt();
    getchar();
    return 0;
}

void rate()
{
    file *fp, *out;
    char c;
    int i;

    if((fp=fopen("project_huffman.txt","r"))==null)
    {
        printf("project_huffman.txt文件打开失败..\n");
        return ;
    }
    while(!feof(fp))
    {
        c = fgetc(fp);
        for(i=0; i<=127; i++)
        {
            if(c == i)
            {
                num++;
                n[i]++;
                break;
            }
        }
    }
    fclose(fp);
    //printf("%d",num);//test
    out = fopen("rate.txt","w");	//创建文件用于存放数据
    if(out == null)
    {
        printf("rate.txt打开失败");
        return;
    }
    else
    {
        for(i=0; i<127; i++)
        {
            if(n[i]>0)
            {
                symbrate[i]=(double)n[i]/num;
                fprintf(out,"%d %c %d %lf\n",i,i,n[i],symbrate[i]);
            }

        }
        fprintf(out,"project_huffman.txt 字符总数: %d\n",num);
        fclose(out);


    }
    return;
}

void sort()
{
    int i, j;
    int test = 0;
    struct tab t;

    for(i=0; i<127; i++)
    {
        if(n[i] > 0)
        {
            m++;
            tab[test].ch = i;
            tab[test].ch_num = n[i];
            test++;
        }

    }

    for(i=0; i