哈夫曼编码c语言代码
时间: 2023-07-26 21:03:31 浏览: 56
以下是哈夫曼编码的 C 语言实现代码:
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX_TREE_HT 100
// 哈夫曼树结点
struct MinHeapNode {
char data;
unsigned freq;
struct MinHeapNode *left, *right;
};
// 哈夫曼树
struct MinHeap {
unsigned size;
unsigned capacity;
struct MinHeapNode **array;
};
// 创建一个新的哈夫曼树结点
struct MinHeapNode *newNode(char data, unsigned freq) {
struct MinHeapNode *node = (struct MinHeapNode *)malloc(sizeof(struct MinHeapNode));
node->left = node->right = NULL;
node->data = data;
node->freq = freq;
return node;
}
// 创建一个哈夫曼树
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;
}
// 交换两个哈夫曼树结点
void swapMinHeapNode(struct MinHeapNode **a, struct MinHeapNode **b) {
struct MinHeapNode *t = *a;
*a = *b;
*b = t;
}
// 最小堆化
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);
}
}
// 判断是否为叶子结点
int isLeaf(struct MinHeapNode *root) {
return !(root->left) && !(root->right);
}
// 创建并构建最小堆
struct MinHeap *buildMinHeap(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;
int n = (minHeap->size - 1) / 2;
for (int i = n; i >= 0; --i)
minHeapify(minHeap, i);
return minHeap;
}
// 把最小堆中的两个最小结点合并,生成新的结点
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;
}
// 插入结点到最小堆
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;
}
// 建立哈夫曼树
struct MinHeapNode *buildHuffmanTree(char data[], int freq[], int size) {
struct MinHeapNode *left, *right, *top;
struct MinHeap *minHeap = buildMinHeap(data, freq, size);
while (minHeap->size != 1) {
left = extractMin(minHeap);
right = extractMin(minHeap);
top = newNode('$', left->freq + right->freq);
top->left = left;
top->right = right;
insertMinHeap(minHeap, top);
}
return extractMin(minHeap);
}
// 打印哈夫曼编码
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);
for (int i = 0; i < top; ++i)
printf("%d", arr[i]);
printf("\n");
}
}
// 哈夫曼编码主函数
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() {
char data[] = {'a', 'b', 'c', 'd', 'e', 'f'};
int freq[] = {5, 9, 12, 13, 16, 45};
int size = sizeof(data) / sizeof(data[0]);
HuffmanCodes(data, freq, size);
return 0;
}
```
以上代码是一个简单的哈夫曼编码实现,可以根据需要进行修改和扩展。