C++数据结构实现构造哈夫曼树进行编码

【实验内容】：

                给定权值{7,19,2,6,32,3,21,10}，构造哈夫曼树并进行编码。

结果图：

CODE :

/*
     Author :LCH南安
*/
#include 
#include 
#define max 10000
#define maxleaf 100
#define maxnode 200
#define maxbit 30

typedef struct
{
    char data;     //结点值
    double weight; //权值
    int flag;
    int parent, lchild, rchild;
} BTNode;

typedef struct
{
    int bit[maxbit];
    int start;
} BCode;

//哈夫曼树结点初始化
void InitHT(BTNode bt[], BCode bcd[], int n)
{
    if (n <= 1)
        return;
    int i;
    for (i = 0; i < 2 * n - 1; i++) //将指向父亲、左右孩子的指针置空
    {
        bt[i].weight = 0;
        bt[i].parent = 0;
        bt[i].flag = 0;
        bt[i].lchild = -1;
        bt[i].rchild = -1;
    }
    printf("输入每个叶子结点的符号：");
    for (i = 0; i < n; i++)
    {
        getchar(); //要放getchar接收回车符
        scanf("%c", &bt[i].data);
    }
    printf("输入对应结点权值：");
    for (i = 0; i < n; i++)
    {
        getchar();
        scanf("%lf", &bt[i].weight);
    }
}
//构造哈夫曼树，生成哈夫曼编码
void CreateHT(BTNode bt[], BCode bcd[], int n)
{
    int i, j;
    int m1, m2, x1, x2, c, p;
    BCode cd;
    for (i = 0; i < n - 1; i++)
    {
        m1 = m2 = max;
        x1 = x2 = 0;
        for (j = 0; j < n + i; j++)
        {
            if (bt[j].weight < m1 && bt[j].flag == 0)
            {
                m2 = m1;
                x2 = x1;
                m1 = bt[j].weight;
                x1 = j;
            }
            else
            {
                if (bt[j].weight < m2 && bt[j].flag == 0)
                {
                    m2 = bt[j].weight;
                    x2 = j;
                }
            }
        }
        bt[x1].parent = n + i;
        bt[x2].parent = n + i;
        bt[x1].flag = 1;
        bt[x2].flag = 1;
        bt[n + i].weight = bt[x1].weight + bt[x2].weight;
        bt[n + i].lchild = x1;
        bt[n + i].rchild = x2;
    }
    for (i = 0; i < n; i++) //生成哈夫曼编码
    {
        cd.start = n - 1;
        c = i;
        p = bt[c].parent;
        while (p != 0)
        {
            if (bt[p].lchild == c)
                cd.bit[cd.start] = 0;
            else
                cd.bit[cd.start] = 1;
            cd.start--;
            c = p;
            p = bt[c].parent;
        }
        for (j = cd.start + 1; j < n; j++)
        {
            bcd[i].bit[j] = cd.bit[j];
            bcd[i].start = cd.start;
        }
    }
}

//输出哈夫曼编码
void OutputHT(BTNode bt[], BCode bcd[], int n)
{
    int i, j;
    for (i = 0; i < n; i++)
    {
        printf("%c的编码为：", bt[i].data);
        for (j = bcd[i].start + 1; j < n; j++)
        {
            printf("%d", bcd[i].bit[j]);
        }
        printf("\n");
    }
}

int main()
{
    BTNode bt[max]; //存放所有结点数组
    BCode bcd[maxleaf];
    int n, i;
    printf("输入数据个数：");
    scanf("%d", &n);
    InitHT(bt, bcd, n);
    CreateHT(bt, bcd, n);
    OutputHT(bt, bcd, n);
    return 0;
}