给个范式Huffman编码的c代码

### 回答1：

我提供一段简单的 Huffman 编码 C 代码：#include <stdio.h>
#include <stdlib.h>

struct node {
char data;
int freq;
struct node * left;
struct node * right;
};

struct node * huffmanTree(char data[], int freq[], int size)
{
struct node * left, * right, * top;

// 建立最小堆
for (int i = size / 2 - 1; i >= 0; i--)
{
int j = i;

while (j <= size / 2 - 1)
{
int k = 2 * j + 1;

if (k + 1 < size && freq[k] > freq[k + 1])
k++;

if (freq[j] <= freq[k])
break;

int temp = freq[k];
freq[k] = freq[j];
freq[j] = temp;

char c = data[k];
data[k] = data[j];
data[j] = c;

j = k;
}
}

// 建立 Huffman 树
for (int i = 1; i <= size - 1; i++)
{
left = (struct node*)malloc(sizeof(struct node));
right = (struct node*)malloc(sizeof(struct node));

// 取出两个最小的节点
left->data = data[0];
left->freq = freq[0];
left->left = left->right = NULL;

right->data = data[1];
right->freq = freq[1];
right->left = right->right = NULL;

freq[0] = freq[0] + freq[1];
freq[1] = freq[size - 1];
size--;

// 重新建立最小堆
int j = 0;
while (j <= size / 2 - 1)
{
int k = 2 * j + 1;

if (k + 1 < size && freq[k] > freq[k + 1])
k++;

if (freq[j] <= freq[k])
break;

int temp = freq[k];
freq[k] = freq[j];
freq[j] = temp;

char c = data[k];
data[k] = data[j];
data[j] = c;

j = k;
}

top = (struct node*)malloc(sizeof(struct node));
top->freq = left->freq + right->freq;
top->data = '$';
top->left = left;
top->right = right;
}

return top;
}

### 回答2：
Huffman编码是一种无损压缩算法，用于对数据进行编码，以减少数据传输和存储的成本。下面是一个示例的Huffman编码的C代码范式：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// 结点结构体
typedef struct Node {
    unsigned char data; // 字符数据
    int frequency; // 字符出现的频率
    struct Node *left, *right; // 左右子节点
} Node;

// 创建新结点
Node* createNode(unsigned char data, int frequency)
{
    Node* newNode = (Node*)malloc(sizeof(Node));
    newNode->data = data;
    newNode->frequency = frequency;
    newNode->left = newNode->right = NULL;
    return newNode;
}

// 构建Huffman树
Node* buildHuffmanTree(unsigned char data[], int frequency[], int size)
{
    Node *left, *right, *top;

    // 创建一个优先队列，用于存储Huffman树的结点
    PriorityQueue* pq = createPriorityQueue();

    // 将每个字符的频率作为优先级，构建Huffman树的结点
    for (int i = 0; i < size; ++i) {
        enqueue(pq, createNode(data[i], frequency[i]));
    }

    // 直到只剩下一个结点，即为Huffman树的根结点
    while (getSize(pq) > 1) {
        left = dequeue(pq);
        right = dequeue(pq);

        top = createNode('$', left->frequency + right->frequency); // $表示内部结点
        top->left = left;
        top->right = right;

        enqueue(pq, top);
    }

    return dequeue(pq);
}

// 递归地打印Huffman编码
void printHuffmanCodes(Node* root, char arr[], int top)
{
    // 叶子结点的编码位于arr[]数组中
    if (root->left) {
        arr[top] = '0';
        printHuffmanCodes(root->left, arr, top + 1);
    }

    if (root->right) {
        arr[top] = '1';
        printHuffmanCodes(root->right, arr, top + 1);
    }

    // 只有一个字符的结点时，打印编码
    if (isLeaf(root)) {
        printf("%c: ", root->data);
        for (int i = 0; i < top; ++i) {
            printf("%c", arr[i]);
        }
        printf("\n");
    }
}

// Huffman编码的主函数
void huffmanCoding(unsigned char data[], int frequency[], int size)
{
    // 构建Huffman树
    Node* root = buildHuffmanTree(data, frequency, size);

    // 用于存储编码的临时数组
    char arr[MAX_TREE_HT], top = 0;

    // 打印Huffman编码
    printHuffmanCodes(root, arr, top);
}

int main()
{
    unsigned char data[] = { 'a', 'b', 'c', 'd', 'e', 'f' };
    int frequency[] = { 5, 9, 12, 13, 16, 45 };
    int size = sizeof(data) / sizeof(data[0]);

    // 运行Huffman编码
    huffmanCoding(data, frequency, size);

    return 0;
}

这是一个简单的Huffman编码的C代码范式示例。注意，代码中使用了一些未定义的函数和数据结构，如`PriorityQueue`、`enqueue`等，需要根据实际情况进行定义和实现。此外，还需要添加一些错误检查和释放内存的代码，以确保程序的稳定性和健壮性。

### 回答3：
以下是一个用C语言实现的Huffman编码的范例代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>

#define MAX_TREE_HT 100

struct MinHeapNode {
    char data;
    unsigned freq;
    struct MinHeapNode *left, *right;
};

struct MinHeap {
    unsigned size;
    unsigned capacity;
    struct MinHeapNode **array;
};

struct MinHeapNode* newNode(char data, unsigned freq)
{
    struct MinHeapNode* temp = (struct MinHeapNode*)malloc(
        sizeof(struct MinHeapNode));
    temp->left = temp->right = NULL;
    temp->data = data;
    temp->freq = freq;
    return temp;
}

struct MinHeap* createMinHeap(unsigned capacity)
{
    struct MinHeap* minHeap = (struct MinHeap*)malloc(
        sizeof(struct MinHeap));
    minHeap->size = 0;
    minHeap->capacity = capacity;
    minHeap->array = (struct MinHeapNode**)malloc(
        minHeap->capacity * sizeof(struct MinHeapNode*));
    return minHeap;
}

void swapMinHeapNode(struct MinHeapNode** a,
                     struct MinHeapNode** b)
{
    struct MinHeapNode* t = *a;
    *a = *b;
    *b = t;
}

void minHeapify(struct MinHeap* minHeap, int idx)
{
    int smallest = idx;
    int left = 2 * idx + 1;
    int right = 2 * idx + 2;

    if (left < minHeap->size
        && minHeap->array[left]->freq < minHeap->array[smallest]->freq)
        smallest = left;

    if (right < minHeap->size
        && minHeap->array[right]->freq < minHeap->array[smallest]->freq)
        smallest = right;

    if (smallest != idx) {
        swapMinHeapNode(&minHeap->array[smallest], &minHeap->array[idx]);
        minHeapify(minHeap, smallest);
    }
}

bool isSizeOne(struct MinHeap* minHeap)
{
    return (minHeap->size == 1);
}

struct MinHeapNode* extractMin(struct MinHeap* minHeap)
{
    struct MinHeapNode* temp = minHeap->array[0];
    minHeap->array[0] = minHeap->array[minHeap->size - 1];

    --minHeap->size;
    minHeapify(minHeap, 0);

    return temp;
}

void insertMinHeap(struct MinHeap* minHeap,
                   struct MinHeapNode* minHeapNode)
{
    ++minHeap->size;
    int i = minHeap->size - 1;

    while (i && minHeapNode->freq < minHeap->array[(i - 1) / 2]->freq) {
        minHeap->array[i] = minHeap->array[(i - 1) / 2];
        i = (i - 1) / 2;
    }

    minHeap->array[i] = minHeapNode;
}

void buildMinHeap(struct MinHeap* minHeap)
{
    int n = minHeap->size - 1;
    int i;

    for (i = (n - 1) / 2; i >= 0; --i)
        minHeapify(minHeap, i);
}

void printArr(int arr[], int n)
{
    int i;
    for (i = 0; i < n; ++i)
        printf("%d", arr[i]);

    printf("\n");
}

bool isLeaf(struct MinHeapNode* root)
{
    return !(root->left) && !(root->right);
}

struct MinHeap* createAndBuildMinHeap(char data[], int freq[], int size)
{
    struct MinHeap* minHeap = createMinHeap(size);

    for (int i = 0; i < size; ++i)
        minHeap->array[i] = newNode(data[i], freq[i]);

    minHeap->size = size;
    buildMinHeap(minHeap);

    return minHeap;
}

struct MinHeapNode* buildHuffmanTree(char data[], int freq[], int size)
{
    struct MinHeapNode *left, *right, *top;

    struct MinHeap* minHeap = createAndBuildMinHeap(data, freq, size);

    while (!isSizeOne(minHeap)) {
        left = extractMin(minHeap);
        right = extractMin(minHeap);

        top = newNode('$', left->freq + right->freq);
        top->left = left;
        top->right = right;

        insertMinHeap(minHeap, top);
    }

    return extractMin(minHeap);
}

void printCodes(struct MinHeapNode* root, int arr[],
                int top)
{
    if (root->left) {
        arr[top] = 0;
        printCodes(root->left, arr, top + 1);
    }

    if (root->right) {
        arr[top] = 1;
        printCodes(root->right, arr, top + 1);
    }

    if (isLeaf(root)) {
        printf("%c: ", root->data);
        printArr(arr, top);
    }
}

void HuffmanCodes(char data[], int freq[], int size)
{
    struct MinHeapNode* root
        = buildHuffmanTree(data, freq, size);

    int arr[MAX_TREE_HT], top = 0;

    printCodes(root, arr, top);
}

int main()
{
    int n;
    printf("请输入字符的数量: ");
    scanf("%d", &n);
    char data[n];
    int freq[n];
    printf("请输入字符及其频率：\n");
    for (int i = 0; i < n; i++) {
        scanf("%s %d", &data[i], &freq[i]);
    }
    int size = sizeof(data) / sizeof(data[0]);

    printf("Huffman Codes:\n");
    HuffmanCodes(data, freq, size);

    return 0;
}

以上是一个使用C语言实现的Huffman编码的范例代码，通过输入字符及其频率，可以输出对应的Huffman编码。