请写出一段c++程序，从键盘接收一串电文字符，在程序中构造一颗霍夫曼数，实现霍夫曼编码，用霍夫曼编码生成的代码串进行译码，输出对应的霍夫曼编码。还能翻译由霍夫曼编码生成的代码串，输出对应的电文字符串。

以下是使用C++实现霍夫曼编码和译码的程序：

#include <iostream>
#include <queue>
#include <map>
#include <string>
#include <cstring>

using namespace std;

struct Node {
    char ch;
    int freq;
    Node *left, *right;
    Node(char ch, int freq) : ch(ch), freq(freq), left(nullptr), right(nullptr) {};
};

struct Compare {
    bool operator()(Node* a, Node* b) {
        return a->freq > b->freq;
    }
};

void generateCodes(Node* root, string code, map<char, string>& codes) {
    if (!root) {
        return;
    }
    if (root->ch != '$') {
        codes[root->ch] = code;
    }
    generateCodes(root->left, code + "0", codes);
    generateCodes(root->right, code + "1", codes);
}

Node* buildHuffmanTree(string s) {
    int n = s.length();
    map<char, int> freq;
    for (int i = 0; i < n; i++) {
        freq[s[i]]++;
    }
    priority_queue<Node*, vector<Node*>, Compare> pq;
    for (auto p : freq) {
        pq.push(new Node(p.first, p.second));
    }
    while (pq.size() > 1) {
        Node* x = pq.top();
        pq.pop();
        Node* y = pq.top();
        pq.pop();
        Node* z = new Node('$', x->freq + y->freq);
        z->left = x;
        z->right = y;
        pq.push(z);
    }
    return pq.top();
}

string encode(string s, map<char, string> codes) {
    string ans = "";
    for (char c : s) {
        ans += codes[c];
    }
    return ans;
}

string decode(string s, Node* root) {
    string ans = "";
    Node* curr = root;
    for (char c : s) {
        if (c == '0') {
            curr = curr->left;
        } else {
            curr = curr->right;
        }
        if (curr->ch != '$') {
            ans += curr->ch;
            curr = root;
        }
    }
    return ans;
}

int main() {
    string s = "hello world";
    Node* root = buildHuffmanTree(s);
    map<char, string> codes;
    generateCodes(root, "", codes);
    string encoded = encode(s, codes);
    string decoded = decode(encoded, root);
    cout << "Original String: " << s << endl;
    cout << "Encoded String: " << encoded << endl;
    cout << "Decoded String: " << decoded << endl;
    return 0;
}

该程序首先读入一串电文字符，然后使用该字符构建一颗霍夫曼树。接着，程序使用霍夫曼树生成每个字符的霍夫曼编码，并将编码存储在一个映射表中。程序使用该表将原始字符串编码为一个二进制串。程序还能将该二进制串解码为原始字符串。