Huffman树进行编码和译码

//编码
#include<iostream> 
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<queue>
#include<fstream>
#include<map> 
using namespace std;typedef struct HuffmanNode{int w;//节点的权值 int ld, rd;//左右孩子节点 int p;//父节点 char ch;//当前节点的字符HuffmanNode(){ld = rd = p = -1;}
}huffmanNode, *pHuffmanNode;typedef pair<int, int> pii;//haffuman节点和它的编号 bool operator > (pii x, pii y){return x.first > y.first;
}struct Huffman{int cntNode;//总结点的个数 string orgCode;string huffmanCode;pHuffmanNode huffman =    NULL;priority_queue<pii, vector<pii>, greater<pii> >qNode;map<string, char> huffmanMapx;//哈夫曼编码对应字符 map<char, string> huffmanMapy;//字符对应哈夫曼编码 void initHuffman(char *str){orgCode = str;cntNode = 0;int cnt[150];//统计每一个节点的个数 memset(cnt, 0, sizeof(cnt));for(int i=0; str[i]; ++i){if(cnt[str[i]]==0) ++cntNode;++cnt[str[i]];}huffman = new HuffmanNode[2*(cntNode)];int index = 0;for(int i=0; i<150; ++i){if(cnt[i]!=0){huffman[index].w = cnt[i];huffman[index].ch = i;qNode.push(make_pair(huffman[index].w, index));++index;}}while(qNode.size()>=2) {pii ldPii = qNode.top();qNode.pop();pii rdPii = qNode.top();qNode.pop();huffman[index].w = ldPii.first + rdPii.first;huffman[index].ld = ldPii.second;huffman[index].rd = rdPii.second;huffman[ldPii.second].p = index;huffman[rdPii.second].p = index;qNode.push(make_pair(huffman[index].w, index));++index; }}void huffmanCoding() {for(int i=0; i<cntNode; ++i){//从每一个孩子节点向上寻找 string code = "";for(int child=i, p=huffman[child].p; ~p; child = p, p = huffman[child].p) {if(huffman[p].ld == child){//左子树 code += '0';} else if(huffman[p].rd == child){//右子树code += '1';} }reverse(code.begin(), code.end());huffmanMapx.insert(make_pair(code, huffman[i].ch));huffmanMapy.insert(make_pair(huffman[i].ch, code));}}void outHuffmanTree(fstream &fout, int f){if(huffman[f].ld==-1 && huffman[f].rd==-1){fout<<0<<" ";return ;} else {fout<<1<<" ";outHuffmanTree(fout, huffman[f].ld);outHuffmanTree(fout, huffman[f].rd);}}void outHuffmanCode(){huffmanCode = "";//存储字符串的哈夫曼编码之后的内容 fstream fout("out.txt", ios_base::out);for(int i=0; i<orgCode.length(); ++i){huffmanCode += huffmanMapy[orgCode[i]];}cout<<huffmanCode<<endl;fout<<huffmanCode<<endl;//想文件中输入huffman编码int f = 2*cntNode-2;//huffman树的父节点outHuffmanTree(fout, f);fout<<endl;for(map<string, char>::iterator it = huffmanMapx.begin(); it!=huffmanMapx.end(); ++it){cout<<it->first << " -> " << it->second<<endl; fout<<it->first<<" "<<it->second<<endl; //向文件中输入HuffmanMap }}
};int main(){char str[100];Huffman huffman;gets(str);huffman.initHuffman(str);huffman.huffmanCoding();huffman.outHuffmanCode();return 0;
}

//译码
#include<iostream> 
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<queue>
#include<fstream>
#include<map> 
using namespace std;typedef struct HuffmanTreeNode{HuffmanTreeNode *ld, *rd;HuffmanTreeNode(){ld = NULL;rd = NULL;}
} *pHuffmanTreeNode;struct Huffman{pHuffmanTreeNode T;string code;map<string, char>huffmanMapx;void buildT(fstream &fin, pHuffmanTreeNode &T){int w;fin>>w;T = new HuffmanTreeNode(); if(w==0)return ;buildT(fin, T->ld);buildT(fin, T->rd);}void outT(pHuffmanTreeNode T){if(T->ld != NULL){cout<<0<<endl;outT(T->ld); }else return;if(T->rd != NULL){cout<<1<<endl;outT(T->rd); }}void initHuffmanTree(){fstream fin("in.txt", ios_base::in);T = NULL;fin>>code;buildT(fin, T);//outT(T);string mapContent;while(getline(fin, mapContent)){int index = mapContent.find_first_of(' ');huffmanMapx.insert(make_pair(mapContent.substr(0, index), mapContent[index+1]));}}void outHuffmanEncode(){string encode = "", cd="";initHuffmanTree();pHuffmanTreeNode p = T;for(int i=0; i<code.length(); ++i){if(p->ld==NULL && p->rd==NULL){encode+=huffmanMapx[cd];cd="";--i;p=T;} else {cd+=code[i];if(code[i]=='0')p=p->ld;else if(code[i]=='1')p=p->rd;}if(i==code.length()-1) encode+=huffmanMapx[cd];}cout<<encode<<endl;}
};int main(){Huffman huffman;huffman.outHuffmanEncode();return 0;
}

操作流程：

文本内容：aaaaaaabbbbbccdddd, and I am a student, my name is hjzgg!

1.首先利用''编码"工具将文本编码，会输出一个out.txt的文本，将out.txt文本中的内容发送给你的好友。

2.接受到out.txt文本的内容后，将内容复制到文本名为in.txt的文件中，利用"译码"工具（保证in.txt和译码工具在同一目录下）可以查看文本内容。

3.其中out.txt文本的格式如下：