这是一个简单的二叉树模板示例

C++示例：

cpp
#include <iostream>

class TreeNode {
public:
    int data;
    TreeNode* left;
    TreeNode* right;

    TreeNode(int val) : data(val), left(nullptr), right(nullptr) {}
};

class BinaryTree {
public:
    TreeNode* root;

    BinaryTree() : root(nullptr) {}

    void insert(int val) {
        root = insertNode(root, val);
    }

    TreeNode* insertNode(TreeNode* node, int val) {
        if (node == nullptr) {
            return new TreeNode(val);
        }

        if (val < node->data) {
            node->left = insertNode(node->left, val);
        } else {
            node->right = insertNode(node->right, val);
        }

        return node;
    }

    void inorderTraversal(TreeNode* node) {
        if (node == nullptr) {
            return;
        }

        inorderTraversal(node->left);
        std::cout << node->data << " ";
        inorderTraversal(node->right);
    }
};

int main() {
    BinaryTree tree;
    tree.insert(5);
    tree.insert(3);
    tree.insert(7);
    tree.insert(2);
    tree.insert(4);
    tree.insert(6);
    tree.insert(8);

    tree.inorderTraversal(tree.root);
    return 0;
}

C示例：

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

struct TreeNode {
    int data;
    struct TreeNode* left;
    struct TreeNode* right;
};

struct TreeNode* createNode(int val) {
    struct TreeNode* node = (struct TreeNode*)malloc(sizeof(struct TreeNode));
    node->data = val;
    node->left = NULL;
    node->right = NULL;
    return node;
}

struct TreeNode* insertNode(struct TreeNode* node, int val) {
    if (node == NULL) {
        return createNode(val);
    }

    if (val < node->data) {
        node->left = insertNode(node->left, val);
    } else {
        node->right = insertNode(node->right, val);
    }

    return node;
}

void inorderTraversal(struct TreeNode* node) {
    if (node == NULL) {
        return;
    }

    inorderTraversal(node->left);
    printf("%d ", node->data);
    inorderTraversal(node->right);
}

int main() {
    struct TreeNode* root = NULL;
    root = insertNode(root, 5);
    root = insertNode(root, 3);
    root = insertNode(root, 7);
    root = insertNode(root, 2);
    root = insertNode(root, 4);
    root = insertNode(root, 6);
    root = insertNode(root, 8);

    inorderTraversal(root);

    return 0;
}

Go示例：

go
package main

import "fmt"

type TreeNode struct {
    data  int
    left  *TreeNode
    right *TreeNode
}

func createNode(val int) *TreeNode {
    return &TreeNode{data: val, left: nil, right: nil}
}

func insertNode(node *TreeNode, val int) *TreeNode {
    if node == nil {
        return createNode(val)
    }

    if val < node.data {
        node.left = insertNode(node.left, val)
    } else {
        node.right = insertNode(node.right, val)
    }

    return node
}

func inorderTraversal(node *TreeNode) {
    if node == nil {
        return
    }

    inorderTraversal(node.left)
    fmt.Print(node.data, " ")
    inorderTraversal(node.right)
}

func main() {
    var root *TreeNode
    root = insertNode(root, 5)
    root = insertNode(root, 3)
    root = insertNode(root, 7)
    root = insertNode(root, 2)
    root = insertNode(root, 4)
    root = insertNode(root, 6)
    root = insertNode(root, 8)

    inorderTraversal(root)
}