编辑“︁C 语言二叉搜索树”︁（章节）

=== 案例：单词频率统计 ===
以下程序使用BST统计文本中单词的出现频率：
<syntaxhighlight lang="c">
typedef struct WordNode {
    char word[50];
    int count;
    struct WordNode *left, *right;
} WordNode;

WordNode* insertWord(WordNode *root, const char *word) {
    if (root == NULL) {
        WordNode *newNode = (WordNode*)malloc(sizeof(WordNode));
        strcpy(newNode->word, word);
        newNode->count = 1;
        newNode->left = newNode->right = NULL;
        return newNode;
    }
    int cmp = strcmp(word, root->word);
    if (cmp < 0) {
        root->left = insertWord(root->left, word);
    } else if (cmp > 0) {
        root->right = insertWord(root->right, word);
    } else {
        root->count++;
    }
    return root;
}
</syntaxhighlight>