用C语言实现字典树

好的，以下是用C语言实现字典树的示例代码：

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

#define MAX_CHILDREN 26

struct TrieNode {
    int count;  // 记录单词出现次数
    struct TrieNode* children[MAX_CHILDREN];
};

struct Trie {
    struct TrieNode* root;
};

struct TrieNode* create_node() {
    struct TrieNode* node = (struct TrieNode*)malloc(sizeof(struct TrieNode));
    node->count = 0;
    for (int i = 0; i < MAX_CHILDREN; i++) {
        node->children[i] = NULL;
    }
    return node;
}

void insert(struct Trie* trie, char* word) {
    struct TrieNode* p = trie->root;
    for (int i = 0; i < strlen(word); i++) {
        int index = word[i] - 'a';
        if (p->children[index] == NULL) {
            p->children[index] = create_node();
        }
        p = p->children[index];
    }
    p->count++;
}

int search(struct Trie* trie, char* word) {
    struct TrieNode* p = trie->root;
    for (int i = 0; i < strlen(word); i++) {
        int index = word[i] - 'a';
        if (p->children[index] == NULL) {
            return 0;
        }
        p = p->children[index];
    }
    return p->count;
}

int main() {
    struct Trie trie;
    trie.root = create_node();
    insert(&trie, "apple");
    insert(&trie, "app");
    insert(&trie, "application");
    int count = search(&trie, "app");
    printf("单词 app 出现的次数为：%d\n", count);
    return 0;
}

以上代码中，`create_node` 函数用于创建字典树节点，`insert` 函数用于向字典树中插入单词，`search` 函数用于在字典树中查找单词出现的次数。`main` 函数则测试了该字典树在插入单词 `"apple"`、`"app"`、`"application"` 后查找单词 `"app"` 出现的次数的结果。