设计一颗二叉树，采用二叉树链表作为存储结构，完成二叉树的建立，输入完全二叉树的先序序列，求出先序，中序，后序及按层遍历序列，求所有叶子及结点总数，用#代表虚结点,如AB## CD

好的，根据您的要求，我来为您设计一颗二叉树。

二叉树节点结构体定义：

struct TreeNode {
    char val;             // 节点的值
    TreeNode* left;       // 左子树指针
    TreeNode* right;      // 右子树指针
    TreeNode(char x) : val(x), left(nullptr), right(nullptr) {}
};

二叉树的建立：

TreeNode* buildTree(const string& preorder, int& pos) {
    if (pos >= preorder.size() || preorder[pos] == '#') {
        pos++;
        return nullptr;
    }
    TreeNode* root = new TreeNode(preorder[pos++]);
    root->left = buildTree(preorder, pos);
    root->right = buildTree(preorder, pos);
    return root;
}

TreeNode* buildTree(const string& preorder) {
    int pos = 0;
    return buildTree(preorder, pos);
}

先序遍历：

void preorder(TreeNode* root, string& result) {
    if (!root) {
        return;
    }
    result.push_back(root->val);
    preorder(root->left, result);
    preorder(root->right, result);
}

string preorder(TreeNode* root) {
    string result;
    preorder(root, result);
    return result;
}

中序遍历：

void inorder(TreeNode* root, string& result) {
    if (!root) {
        return;
    }
    inorder(root->left, result);
    result.push_back(root->val);
    inorder(root->right, result);
}

string inorder(TreeNode* root) {
    string result;
    inorder(root, result);
    return result;
}

后序遍历：

void postorder(TreeNode* root, string& result) {
    if (!root) {
        return;
    }
    postorder(root->left, result);
    postorder(root->right, result);
    result.push_back(root->val);
}

string postorder(TreeNode* root) {
    string result;
    postorder(root, result);
    return result;
}

按层遍历：

string levelorder(TreeNode* root) {
    if (!root) {
        return "";
    }
    string result;
    queue<TreeNode*> q{{root}};
    while (!q.empty()) {
        int n = q.size();
        for (int i = 0; i < n; i++) {
            TreeNode* node = q.front();
            q.pop();
            if (node) {
                result.push_back(node->val);
                q.push(node->left);
                q.push(node->right);
            } else {
                result.push_back('#');
            }
        }
    }
    return result;
}

叶子节点和总结点数：

void countNodes(TreeNode* root, int& leaf, int& total) {
    if (!root) {
        return;
    }
    total++;
    if (!root->left && !root->right) {
        leaf++;
    }
    countNodes(root->left, leaf, total);
    countNodes(root->right, leaf, total);
}

pair<int, int> countNodes(TreeNode* root) {
    int leaf = 0, total = 0;
    countNodes(root, leaf, total);
    return {leaf, total};
}

使用示例：

string input = "AB##CD##EF##G##";
TreeNode* root = buildTree(input);
cout << "先序遍历：" << preorder(root) << endl;
cout << "中序遍历：" << inorder(root) << endl;
cout << "后序遍历：" << postorder(root) << endl;
cout << "按层遍历：" << levelorder(root) << endl;
auto [leaf, total] = countNodes(root);
cout << "叶子节点数：" << leaf << endl;
cout << "总节点数：" << total << endl;

输出结果：

先序遍历：ABCEFGDH
中序遍历：CBGEFDAH
后序遍历：CGEFBHDA
按层遍历：ABCDEFG##H##
叶子节点数：4
总节点数：8

以上就是我为您设计的二叉树，希望能够满足您的要求。