哈弗曼编码

来源：互联网发布：市场进入策略一手数据编辑：程序博客网时间：2024/06/06 08:27
给定任意一个字符串，给出哈弗曼编码
#include <iostream>#include <stdio.h>#include <map>#include <vector>#include <string.h>#include <string>using namespace std;typedef string huff_type;struct huff_node{    huff_node *left,*right;    int wight;    huff_type data;};map<huff_type,int> map_w;/*** 统计每个单词的频率*/map<huff_type ,int> count_fre(char * str){    char buf[2];    buf[1] = 0;    size_t len = strlen(str);    map<huff_type ,int> map_fre;    map_fre.clear();    for(int i=0 ; i<len ; i++)    {        buf[0] = str[i];        huff_type ch = buf;        if(map_fre.find(ch) != map_fre.end())        {            map_fre[ch] = map_fre[ch] + 1;        }        else        {            map_fre[ch] = 1;        }    }    ////    map<huff_type ,int>::iterator it;//    for(it=map_fre.begin();it!=map_fre.end();++it)//        cout<<"key: "<<it->first <<" value: "<<it->second<<endl;    return map_fre;}huff_node * create_huffman(map<huff_type ,int> map_fre){    huff_node **b = new huff_node*[map_fre.size()];    map<huff_type ,int>::iterator it;    int i;    for(it=map_fre.begin(),i=0;it!=map_fre.end();++it,i++)    {//        cout<<"key: "<<it->first <<" value: "<<it->second<<endl;        b[i] = new huff_node();        b[i]->data = it->first;        b[i]->left = b[i]->right = NULL;        b[i]->wight = it->second;    }    int size = map_fre.size() - 1;//    printf("%d",size);    int first,second;    while(size--)    {        first = second = -1;        for(i=0 ; i<map_fre.size() ; i++)        {            if(b[i] == NULL) continue;            if(first == -1)                first = i;            else if(b[i]->wight < b[first]->wight)            {                second = first;                first = i;            }            else if(second == -1 || b[i]->wight < b[second]->wight)                second = i;        }//        cout << "delete first key " << b[first]->data << " value: " << b[first]->wight << endl;//        cout << "delete second key " << b[second]->data << " value: " << b[second]->wight << endl;        huff_node *node = new huff_node();        node->data = b[first]->data + b[second]->data;        node->wight = b[first]->wight + b[second]->wight;        node->left = b[first];        node->right = b[second];        b[first] = node;        b[second] = NULL;    }    return b[first];}map<huff_type,string> huff_code;void get_huffcode(huff_node *node , string now){    if(node==NULL)        return ;    else    {        if(node->left == NULL && node->right==NULL)        {            huff_code[node->data] = now;            //每个字符的huffman编码//            cout << "key " << node->data << " is " << now << endl;        }        else        {            get_huffcode(node->left, now+"0");            get_huffcode(node->right, now+"1");        }    }}int main(){//    map_w.clear();//    char str[255] = "abcdabcaba";    char str[255] ;    gets(str);    map_w = count_fre(str);    huff_node *head = NULL;    head = create_huffman(map_w);    get_huffcode(head, "");    char buf[2];    buf[1] = 0;    for(int i=0 ; i< strlen(str) ; i++)    {        buf[0] = str[i];        cout<<huff_code[buf];    }    cout<<endl;    return 0;}
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