请用C++实现输入HuffmanTree的参考标准底稿

下面是一个简单的参考标准底稿，可以用C++实现输入HuffmanTree：

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

struct TreeNode {
    char data;
    int weight;
    TreeNode* left;
    TreeNode* right;
    TreeNode(char d, int w) : data(d), weight(w), left(NULL), right(NULL) {}
};

struct cmp {
    bool operator()(TreeNode* a, TreeNode* b) {
        return a->weight > b->weight;
    }
};

TreeNode* createHuffmanTree(priority_queue<TreeNode*, vector<TreeNode*>, cmp>& pq) {
    while (pq.size() > 1) {
        TreeNode* left = pq.top(); pq.pop();
        TreeNode* right = pq.top(); pq.pop();
        int sum = left->weight + right->weight;
        TreeNode* parent = new TreeNode('\0', sum);
        parent->left = left;
        parent->right = right;
        pq.push(parent);
    }
    return pq.top();
}

int main() {
    int n;
    cin >> n;
    priority_queue<TreeNode*, vector<TreeNode*>, cmp> pq;
    for (int i = 0; i < n; i++) {
        char c;
        int w;
        cin >> c >> w;
        pq.push(new TreeNode(c, w));
    }
    TreeNode* root = createHuffmanTree(pq);
    // do something with the Huffman tree
    return 0;
}

其中，`TreeNode` 结构体表示一个节点，`cmp` 结构体是一个比较器，用于优先队列的排序。`createHuffmanTree` 函数用于构建Huffman树，输入一个优先队列，输出一个根节点。`main` 函数中首先输入叶子节点的个数 `n`，然后逐个输入每个叶子节点的字符和权重，将它们放入优先队列中，最后调用 `createHuffmanTree` 函数构建Huffman树，并可以对树进行后续操作。