哈夫曼编码

来源：互联网发布：剑桥史系列知乎编辑：程序博客网时间：2024/06/06 05:40

哈夫曼编码的首要思想就是，每次选出两个权重最小的结点，组成一颗新的二叉树，跟结点为两个结点的权重之和，左右孩子为刚选出来的两个结点。然后把这科树放回去，重新选择，直到剩下一颗树。

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using namespace std;typedef struct TNode {    char value;    int fre;    struct TNode* leftNode;    struct TNode* rightNode;}TNode;struct cmp//比较函数，用于优先队列构造最小堆{    bool operator() (TNode *node1,TNode *node2)    {        return node1->fre>node2->fre;     }};int calWeight(TNode* root, int deep);void del(TNode* root);int main(void){    int n,fre;    char value;    while (cin>>n) {        priority_queue<TNode*, vector<TNode*>, cmp> queue;        for (int i = 0; i < n; ++i) {            cin >> value >> fre;            TNode* node = new TNode;            node->value = value;            node->fre = fre;            node->leftNode = NULL;            node->rightNode = NULL;            queue.push(node);        }        while (queue.size()>1) {            struct TNode* node1 = queue.top();            queue.pop();            struct TNode* node2 = queue.top();            queue.pop();            struct TNode* newNode = new TNode;            newNode->fre = node1->fre + node2->fre;            newNode->leftNode = node1;            newNode->rightNode = node2;            queue.push(newNode);        }        if (queue.size() == 1) {            struct TNode* root = queue.top();            queue.pop();            int result = calWeight(root, 0);            cout << result << endl;            del(root);        }        else {            cout << 0 << endl;        }    }    return 0;}//递归计算权重 B(T)=∑f(c)dT(c) 叶子节点权重乘以路径长度，累积int calWeight(TNode* root, int deep) {    if (NULL == root)         return 0;    if ((NULL == root->leftNode) && (NULL == root->rightNode)) {        return deep * (root->fre);    }    int leftWieght = calWeight(root->leftNode,deep+1);    int rightWieght = calWeight(root->rightNode, deep + 1);    return leftWieght + rightWieght;}void del(TNode* root) {    if (NULL == root)        return;    del(root->leftNode);    del(root->rightNode);    delete(root);}

图片出处：
http://www.myexception.cn/program/1829340.html

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