101 lines
2.6 KiB
C
101 lines
2.6 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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typedef struct Node {
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int weight;
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struct Node *left, *right;
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} Node;
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// 比较函数用于 qsort
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int compare(const void* a, const void* b) {
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return (*(Node**)a)->weight - (*(Node**)b)->weight;
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}
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// 创建新节点
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Node* createNode(int weight) {
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Node* newNode = (Node*)malloc(sizeof(Node));
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newNode->weight = weight;
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newNode->left = newNode->right = NULL;
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return newNode;
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}
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// 构建哈夫曼树
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Node* createHuffmanTree(int* weights, int size) {
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Node** nodes = malloc(size * sizeof(Node*));
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for (int i = 0; i < size; i++) {
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nodes[i] = createNode(weights[i]);
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}
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while (size > 1) {
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qsort(nodes, size, sizeof(Node*), compare);// 排序节点数组
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// 创建父节点
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Node* parent = createNode(nodes[0]->weight + nodes[1]->weight);
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parent->left = nodes[0];
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parent->right = nodes[1];
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// 替换前两个最小节点
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nodes[0] = parent;
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for (int i = 1; i < size - 1; i++) {
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nodes[i] = nodes[i + 1];
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}
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size--;
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}
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Node* root = nodes[0];
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free(nodes);
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return root;
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}
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// 递归生成哈夫曼编码
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void encode(Node* node, char* code, int depth) {
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if (node->left == NULL && node->right == NULL) {
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code[depth] = '\0';//终止字符串
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printf("权重: %d, 编码: %s\n", node->weight, code);
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return;
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}
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code[depth] = '0';
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encode(node->left, code, depth + 1);
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code[depth] = '1';
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encode(node->right, code, depth + 1);
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}
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// 解码函数
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void decode(Node* root, const char* encoded) {
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Node* current = root;
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while (*encoded) {
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if (*encoded == '0') {
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current = current->left;
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} else {
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current = current->right;
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}
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// 到达叶子节点，打印权重并返回根节点
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if (current->left == NULL && current->right == NULL) {
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printf("解码权重: %d\n", current->weight);
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current = root; // 回到根节点
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}
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encoded++;// 移动到下一个字符
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}
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}
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// 释放内存
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void freeTree(Node* node) {
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if (node) {
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freeTree(node->left);
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freeTree(node->right);
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free(node);
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}
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}
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int main() {
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int weights[] = {2, 3, 7, 9, 18, 25};
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int size = sizeof(weights) / sizeof(weights[0]);
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Node* root = createHuffmanTree(weights, size);
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char code[100]; // 假设编码长度不会超过100
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printf("编码:\n");
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encode(root, code, 0);
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const char* encoded = "0010101111";
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printf("解码-0010101111:\n");
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decode(root, encoded);
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freeTree(root);
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return 0;
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}
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