树(数据结构)

struct Node {
    char data;
    struct Node* left;
    struct Node* right;
};
 
// 创建一个新节点
struct Node* newNode(char data) {
    struct Node* node = (struct Node*)malloc(sizeof(struct Node));
    node->data = data;
    node->left = node->right = NULL;
    return node;
}
 
// 插入节点到树中
struct Node* insert(struct Node* node, char data) {
    if (node == NULL) {
        return newNode(data);
    }
 
    if (data < node->data)
        node->left = insert(node->left, data);
    else if (data > node->data)
        node->right = insert(node->right, data);
 
    return node;
}