C++实现哈夫曼编码完整代码

C++实现哈夫曼编码完整代码

#include

#include

#include

#include

#include

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 &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 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 &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 &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 result) {

//迭代map容器

map::const_iterator it = result.begin(); while (it != result.end()) {

cout << it->first << ": " << it->second << endl;

++it;

}

}

int main() {

priority_queue 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 result;

huffmanCode(&root, prefix, result);

//检验结果是否正确

testResult(result);

return 0;

}