示例代码：

struct TreeNode {
    int data;
    TreeNode* left;
    TreeNode* right;
<pre class="brush:php;toolbar:false;">TreeNode(int value) : data(value), left(nullptr), right(nullptr) {}

};

class BinaryTree {
private:
    TreeNode* root;
<pre class="brush:php;toolbar:false;">void insertNode(TreeNode*& node, int value) {
    if (!node) {
        node = new TreeNode(value);
    } else if (value < node->data) {
        insertNode(node->left, value);
    } else {
        insertNode(node->right, value);
    }
}

void inorderTr*ersal(TreeNode* node) {
    if (node) {
        inorderTr*ersal(node->left);
        std::cout << node->data << " ";
        inorderTr*ersal(node->right);
    }
}

public: BinaryTree() : root(nullptr) {}

void insert(int value) {
    insertNode(root, value);
}

void inorder() {
    inorderTr*ersal(root);
    std::cout << std::endl;
}

};

int main() {
    BinaryTree tree;
    tree.insert(5);
    tree.insert(3);
    tree.insert(7);
    tree.insert(2);
    tree.insert(4);
<pre class="brush:php;toolbar:false;">std::cout << "Inorder tr*ersal: ";
tree.inorder();  // 输出: 2 3 4 5 7

return 0;

}