C++哈夫曼编码一例

#include

#include
#include
#include
#define MAXVALUE 200           /*权值的最大值*/
#define MAXBIT  30             /*最大的编码位数*/
#define MAXNODE 30             /*初始的最大的结点数*/
struct haffnode
{
    char data;
    int weight;
    int flag;
    int parent;       /*双亲结点的下标*/
    int leftchild;    /*左孩子下标*/
    int rightchild;   /*右孩子下标*/
};
struct haffcode
{
    int bit[MAXNODE];
    int start;        /*编码的起始下标*/
    char data;
    int weight;       /*字符权值*/
};
/*函数说明*/
/************************************************************************/
void pprintf(struct haffcode haffcode[], int n);
/*输出函数*/
void haffmantree(int weight[], int n, struct haffnode hafftree[], char data[]);
/*建立哈夫曼树*/
void haffmancode(struct haffnode hafftree[], int n, struct haffcode haffcode[]);
/*求哈夫曼编码*/
/************************************************************************/




void haffmantree(int weight[], int n, struct haffnode hafftree[], char data[])
/*建立叶结点个数为n，权值数组为weight[]的哈夫曼树*/
{
    int i, j, m1, m2, x1, x2;
/*哈夫曼树hafftree[]初始化，n个叶结点共有2n-1个结点*/
    for(i = 0; i < 2 * n - 1; i++)
    {
        if(i < n) /*叶结点*/
        {
            hafftree[i].data = data[i];
            hafftree[i].weight = weight[i];
        }
        else /*非叶结点*/
        {
            hafftree[i].weight = 0;
            hafftree[i].data = '\0';
        }
        hafftree[i].parent = 0;                     /*初始化没有双亲结点*/
        hafftree[i].flag = 0;
        hafftree[i].leftchild = -1;
        hafftree[i].rightchild = -1;
    }
    for(i = 0; i < n - 1; i++) /*构造哈夫曼树n-1个非叶结点*/
    {
        m1 = m2 = MAXVALUE;
        x1 = x2 = 0;
        for(j = 0; 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(struct haffnode hafftree[], int n, struct haffcode haffcode[])
{
  /*由n个结点的哈夫曼树hafftree[]构成的哈夫曼编码haffcode[]*/
    int i, j, child, parent;
    struct haffcode newcode;
    struct haffcode *cd;
    cd = &newcode;
    for(i = 0; i < n; i++)   /*求n个结点的哈夫曼编码*/
    {
        cd->start = MAXBIT-1;  /*不等长编码的最后一位是n-1*/
        cd->weight = hafftree[i].weight;
        cd->data = hafftree[i].data;    /*取得编码对应值的字符*/
        child = i;
        parent = hafftree[child].parent;
        while(parent != 0)
        {
            if(hafftree[parent].leftchild == child)
                cd->bit[cd->start] = 0;               /*左孩子编码为0*/
            else
                cd->bit[cd->start] = 1;               /*右孩子编码为1*/
            cd->start--;
            child = parent;
            parent = hafftree[child].parent;
        }
        for(j = cd->start + 1; j < MAXBIT; j++)                     /*保存每个叶结点的编码和等长编码的起始位*/
            haffcode[i].bit[j] = cd->bit[j];
        haffcode[i].data = cd->data;
        haffcode[i].start = cd->start;
        haffcode[i].weight = cd->weight;
    }
}
void pprintf(struct haffcode myhaffcode[], int n)
{
    int i, j, count = 0;
    system("cls");
    for(i = 0; i < n; i++)
    {
        printf("字符=%c", myhaffcode[i].data);
        printf("              ");
        printf("weight=%3d", myhaffcode[i].weight);
        printf("              ");
        printf("haffcode=");
        for(j = myhaffcode[i].start + 1; j < MAXBIT; j++)
            printf("%d", myhaffcode[i].bit[j]);
        printf("\n");
        count++;
        if(count == 21)
        getch();
    }
}
int main()
{
    int i, j, n = 27;
    char ch;
    int weight[27]={186,64,13,22,32,103,21,15,47,
                     57,1,5,32,20,57,63,15,1,48,
                     51,80,23,8,18,1,16,1};
    char data[27]={'T','a','b','c','d','e','f','g','h',
                   'i','j','k','l','m','n','o','p','q',
                   'r','s','t','u','v','w','x','y','z'};
    struct haffnode newhaffnode[2 * MAXNODE - 1];
    struct haffcode newcode[MAXNODE];
    struct haffnode *myhafftree = newhaffnode;
    struct haffcode *myhaffcode = newcode;
    if(n > MAXNODE)
    {
        printf("you input the haffnode > MAXNODE,so you input the data is wrong");
        printf("\n");
        return 0;
    }
    system("cls");
    printf("WELCOME!这是一个求哈夫曼编码的问题");
    printf("\n");
    printf("即对所有的字母进行编码后，在根据用户的需要，对用户的要求进行编码。");
    printf("\n");
    getch();
    printf("Ready?Enter,if you want to begin!\n");
    printf("\n");
    getch();
    printf("Now，开始演示哈夫曼编码.");
    getch();
    haffmantree(weight, n, myhafftree, data);
    haffmancode(myhafftree, n, myhaffcode);
    pprintf(myhaffcode, n);
    return 0;
}