用C++写输入完全二叉树的先序序列，用 # 代表虚结点（空指针）， 如 ABD###CE##F###建立二叉树，实现先序、中序和后序以及按层次遍历 序列 求所有叶子及结点总数

好的，以下是使用C++实现题目要求的代码：

#include <iostream>
#include <vector>
#include <queue>
using namespace std;

struct TreeNode {
    char val;
    TreeNode* left;
    TreeNode* right;
    TreeNode(char x) : val(x), left(NULL), right(NULL) {}
};

TreeNode* buildTree(vector<char>& preorder, int& i) {
    if (i >= preorder.size() || preorder[i] == '#') {
        i++;
        return NULL;
    }
    TreeNode* root = new TreeNode(preorder[i++]);
    root->left = buildTree(preorder, i);
    root->right = buildTree(preorder, i);
    return root;
}

vector<char> preorderTraversal(TreeNode* root) {
    vector<char> res;
    if (!root) return res;
    res.push_back(root->val);
    vector<char> left = preorderTraversal(root->left);
    res.insert(res.end(), left.begin(), left.end());
    vector<char> right = preorderTraversal(root->right);
    res.insert(res.end(), right.begin(), right.end());
    return res;
}

vector<char> inorderTraversal(TreeNode* root) {
    vector<char> res;
    if (!root) return res;
    vector<char> left = inorderTraversal(root->left);
    res.insert(res.end(), left.begin(), left.end());
    res.push_back(root->val);
    vector<char> right = inorderTraversal(root->right);
    res.insert(res.end(), right.begin(), right.end());
    return res;
}

vector<char> postorderTraversal(TreeNode* root) {
    vector<char> res;
    if (!root) return res;
    vector<char> left = postorderTraversal(root->left);
    res.insert(res.end(), left.begin(), left.end());
    vector<char> right = postorderTraversal(root->right);
    res.insert(res.end(), right.begin(), right.end());
    res.push_back(root->val);
    return res;
}

vector<vector<char>> levelOrder(TreeNode* root) {
    vector<vector<char>> res;
    if (!root) return res;
    queue<TreeNode*> q{{root}};
    while (!q.empty()) {
        vector<char> level;
        for (int i = q.size(); i > 0; i--) {
            TreeNode* node = q.front(); q.pop();
            level.push_back(node->val);
            if (node->left) q.push(node->left);
            if (node->right) q.push(node->right);
        }
        res.push_back(level);
    }
    return res;
}

pair<int, int> countNodesAndLeaves(TreeNode* root) {
    if (!root) return {0, 0};
    if (!root->left && !root->right) return {1, 1};
    auto left = countNodesAndLeaves(root->left);
    auto right = countNodesAndLeaves(root->right);
    int nodes = left.first + right.first + 1;
    int leaves = left.second + right.second;
    return {nodes, leaves};
}

int main() {
    vector<char> preorder{'A', 'B', 'D', '#', '#', '#', 'C', 'E', '#', '#', 'F', '#', '#', '#'};
    int i = 0;
    TreeNode* root = buildTree(preorder, i);
    vector<char> preorderRes = preorderTraversal(root);
    vector<char> inorderRes = inorderTraversal(root);
    vector<char> postorderRes = postorderTraversal(root);
    vector<vector<char>> levelOrderRes = levelOrder(root);
    pair<int, int> countRes = countNodesAndLeaves(root);
    int nodes = countRes.first;
    int leaves = countRes.second;
    cout << "先序遍历序列：";
    for (auto c : preorderRes) cout << c << " ";
    cout << endl;
    cout << "中序遍历序列：";
    for (auto c : inorderRes) cout << c << " ";
    cout << endl;
    cout << "后序遍历序列：";
    for (auto c : postorderRes) cout << c << " ";
    cout << endl;
    cout << "按层次遍历序列：" << endl;
    for (auto level : levelOrderRes) {
        for (auto c : level) {
            cout << c << " ";
        }
        cout << endl;
    }
    cout << "节点总数：" << nodes << endl;
    cout << "叶子节点数：" << leaves << endl;
    return 0;
}

希望这份代码可以帮助到您！