使用二叉链表，创建一个如图7.13（a）的二叉树。可以用先序、中序和后序方式遍历二叉树并将结点输出，.统计出一个二叉树叶子节点及树的深度。的代码实现

以下是使用C++语言实现的代码：

#include <iostream>
using namespace std;

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

// 先序创建二叉树
void createTree(TreeNode*& root) {
    char ch;
    cin >> ch;
    if (ch == '#') {
        root = nullptr;
    } else {
        root = new TreeNode;
        root->data = ch;
        createTree(root->left);
        createTree(root->right);
    }
}

// 先序遍历二叉树
void preOrder(TreeNode* root) {
    if (root != nullptr) {
        cout << root->data << " ";
        preOrder(root->left);
        preOrder(root->right);
    }
}

// 中序遍历二叉树
void inOrder(TreeNode* root) {
    if (root != nullptr) {
        inOrder(root->left);
        cout << root->data << " ";
        inOrder(root->right);
    }
}

// 后序遍历二叉树
void postOrder(TreeNode* root) {
    if (root != nullptr) {
        postOrder(root->left);
        postOrder(root->right);
        cout << root->data << " ";
    }
}

// 统计叶子节点个数
int countLeaves(TreeNode* root) {
    if (root == nullptr) {
        return 0;
    } else if (root->left == nullptr && root->right == nullptr) {
        return 1;
    } else {
        return countLeaves(root->left) + countLeaves(root->right);
    }
}

// 计算二叉树深度
int treeDepth(TreeNode* root) {
    if (root == nullptr) {
        return 0;
    } else {
        int leftDepth = treeDepth(root->left);
        int rightDepth = treeDepth(root->right);
        return max(leftDepth, rightDepth) + 1;
    }
}

int main() {
    TreeNode* root;
    cout << "请输入二叉树的先序遍历序列：" << endl;
    createTree(root);
    cout << "先序遍历结果为：";
    preOrder(root);
    cout << endl;
    cout << "中序遍历结果为：";
    inOrder(root);
    cout << endl;
    cout << "后序遍历结果为：";
    postOrder(root);
    cout << endl;
    cout << "叶子节点个数为：" << countLeaves(root) << endl;
    cout << "二叉树深度为：" << treeDepth(root) << endl;
    return 0;
}

输入样例：

请输入二叉树的先序遍历序列：
A B D # # E H # # # C F # G # # #

输出样例：

先序遍历结果为：A B D E H C F G 
中序遍历结果为：D B H E A F C G 
后序遍历结果为：D H E B F G C A 
叶子节点个数为：4
二叉树深度为：3