用C语言写出哈夫曼树的代码和注释

以下是用C语言实现哈夫曼树的代码和注释：

#include <stdio.h>
#include <stdlib.h>
#define MAX 100 //定义最大节点数

typedef struct node {
    int weight; //权值
    int parent; //双亲节点下标
    int left; //左孩子节点下标
    int right; //右孩子节点下标
} Node, *HuffmanTree;

//初始化哈夫曼树
void InitHuffmanTree(HuffmanTree ht, int n) {
    int i;
    for (i = 0; i < 2 * n - 1; i++) {
        ht[i].weight = ht[i].parent = ht[i].left = ht[i].right = 0;
    }
}

//构建哈夫曼树
void CreateHuffmanTree(HuffmanTree ht, int n) {
    int i, j, p1, p2, min1, min2;
    for (i = 0; i < n; i++) { //初始化叶子节点
        printf("请输入第%d个权值: ", i + 1);
        scanf("%d", &ht[i].weight);
    }
    for (i = n; i < 2 * n - 1; i++) { //初始化非叶子节点
        ht[i].weight = ht[i].parent = ht[i].left = ht[i].right = 0;
    }
    for (i = n; i < 2 * n - 1; i++) { //构建哈夫曼树
        min1 = min2 = 32767; //初始化最小值为最大整数
        p1 = p2 = 0;
        for (j = 0; j < i; j++) { //找出权值最小的两个节点
            if (ht[j].parent == 0) { //父节点为0表示未被选择过
                if (ht[j].weight < min1) {
                    min2 = min1;
                    p2 = p1;
                    min1 = ht[j].weight;
                    p1 = j;
                } else if (ht[j].weight < min2) {
                    min2 = ht[j].weight;
                    p2 = j;
                }
            }
        }
        ht[p1].parent = i; //将找出的两个节点合并为一个新节点
        ht[p2].parent = i;
        ht[i].left = p1;
        ht[i].right = p2;
        ht[i].weight = min1 + min2;
    }
}

//输出哈夫曼编码
void PrintHuffmanCode(HuffmanTree ht, int n) {
    int i, j, c, p;
    char *code = (char*)malloc(n * sizeof(char)); //分配存储编码的空间
    code[n - 1] = '\0'; //结束符
    for (i = 0; i < n; i++) {
        printf("第%d个节点的哈夫曼编码为: ", i + 1);
        c = i;
        p = ht[i].parent;
        while (p != 0) { //从叶子节点开始向上遍历
            if (ht[p].left == c) { //左子树为0
                code[--n] = '0';
            } else { //右子树为1
                code[--n] = '1';
            }
            c = p;
            p = ht[p].parent;
        }
        printf("%s\n", &code[n]); //输出编码
    }
    free(code); //释放空间
}

int main() {
    int n;
    printf("请输入节点数: ");
    scanf("%d", &n);
    HuffmanTree ht = (HuffmanTree)malloc((2 * n - 1) * sizeof(Node)); //分配存储节点的空间
    InitHuffmanTree(ht, n); //初始化哈夫曼树
    CreateHuffmanTree(ht, n); //构建哈夫曼树
    PrintHuffmanCode(ht, n); //输出哈夫曼编码
    free(ht); //释放空间
    return 0;
}

注释已在代码中添加。以上是一个简单的哈夫曼树实现，仅供参考。