c++实现哈夫曼编码完整代码

#include <iostream>#include <queue>#include <vector>#include <map>#include <string>using namespace std;class Node {  public:    char c; //表示字符    int frequency; //表示该字符出现的次数或频率    Node *left;    Node *right;    Node(char _c, int f, Node *l = NULL, Node *r = NULL)      :c(_c), frequency(f), left(l), right(r) { }    bool operator<(const Node &node) const { //重载<运算法以至于在加入优先队列的时候决定如何处理结点位置      return frequency > node.frequency;    }};void initNode(priority_queue<Node> &q, int nodeNum) {  char c;  int frequency;  for (int i = 0; i < nodeNum; i++) {    cout << "输入字符和结点出现的次数: ";    cin >> c >> frequency;    Node node(c, frequency);    q.push(node);  }}void showNode(priority_queue<Node> q) {  while (!q.empty()) {    Node node = q.top(); q.pop();    cout << node.c << ", " << node.frequency << endl;  }}//构造哈夫曼树void huffmanTree(priority_queue<Node> &q) {  while (q.size() != 1) {    Node *left = new Node(q.top()); q.pop();    Node *right = new Node(q.top()); q.pop();    Node node('R', left->frequency + right->frequency, left, right);    q.push(node);  }}// 打印哈夫曼编码void huffmanCode(Node *root, string &prefix, map<char, string> &result) {  string m_prefix = prefix;  if (root->left == NULL)    return;  //处理左子树  prefix += "0";  //如果是叶子结点则输出,否则递归打印左子树  if (root->left->left == NULL)    result[root->left->c] = prefix;    //cout << root->left->c << ": " << prefix << endl;  else    huffmanCode(root->left, prefix, result);  //还原原来的路径,回溯  prefix = m_prefix;  //处理右子树  prefix += "1";  //如果是叶子结点，则输出, 否则递归打印右子树  if (root->right->right == NULL)    result[root->right->c] = prefix;    //cout << root->right->c << ": " << prefix << endl;  else    huffmanCode(root->right, prefix, result);}void testResult(map<char, string> result) {  //迭代map容器  map<char, string>::const_iterator it = result.begin();  while (it != result.end()) {    cout << it->first << ": " << it->second << endl;    ++it;  }}int main() {  priority_queue<Node> q;  int nodeNum;  //初始化字符信息  cout << "请输入结点个数: ";  cin >> nodeNum;  initNode(q, nodeNum);  //showNode(q);  //构造哈夫曼树  huffmanTree(q);  //构造哈夫曼编码  Node root = q.top();  string prefix = "";  map<char, string> result;  huffmanCode(&root, prefix, result);  //检验结果是否正确  testResult(result);  return 0;}