C++哈弗曼编码

#include <iostream>
 using std::cout;
 using std::cin;
 using std::endl;
 
#include <iomanip>
 using std::setw;
 
// ------------赫夫曼树和赫夫曼编码的存储表示-------------
 typedef  struct
 {
    unsigned int weight;
    unsigned int parent, lchild, rchild;
 } HTNode, * HuffmanTree;         // 动态分配数组存储赫夫曼树
 typedef  char * HuffmanCodeLine;
 typedef  char * * HuffmanCode;   // 动态分配数组存储赫夫曼编码表
 typedef struct{
     unsigned int weight;
     int index;
 }Non_parent;                     //存储没有父节点的HuffmanTree的权重和序号
 
void Select(HuffmanTree &HT, int count, int &min1, int &min2);
 
void HuffmanCoding(HuffmanTree &HT, HuffmanCode &HC, int * w, int n) 
 {                                                  
    // w存放n个字符的权值(均>0), 构造赫夫曼树HT, 
   // 并求出n个字符的赫夫曼编码HC.
    if (n <= 1)
    {
       return;
    }
    int m = 2*n-1;          // n个叶子结点的赫夫曼树共有2*n-1个结点.
    HT = new HTNode[m+1];   // 0号单元未用.
    int i;                  // 循环变量
    HTNode * p;
    for (p=HT+1, i=1; i<=n; ++i, ++p, ++w) // 0号单元未用.
    {
       (*p).weight = *w;
       (*p).parent = 0;
       (*p).lchild = 0;
       (*p).rchild = 0;
    }
    for (; i<=m; ++i, ++p)
    {
       (*p).weight = 0;
       (*p).parent = 0;
       (*p).lchild = 0;
       (*p).rchild = 0;
    }
    int s1, s2;
    for (i=n+1; i<=m; ++i)
    {
       // 建赫夫曼树:

       // 在HT[1...i-1]选择parent为0且weight最小的两个结点, 
      // 其序号分别为s1和s2.
       Select(HT, i-1, s1, s2);
       HT[s1].parent = i;
       HT[s2].parent = i;
       HT[i].lchild = s1;
       HT[i].rchild = s2;
       HT[i].weight = HT[s1].weight + HT[s2].weight;
    }
 #if 1
    // ---------从叶子到根逆向求每个字符的赫夫曼编码---------
    HC = new char*[n+1];             // 分配n个字符编码的头指针向量
                                     // 也是0号单元未用!!!
    char * cd = new char[n];         // 分配求编码的工作空间
    cd[n-1] = '\0';                  // 编码结束码
    int start;
    for (i=1; i<=n; ++i)
    {
       start = n-1;   // 编码结束符位置
       int l;
       unsigned int f;
       for (l=i, f=HT[i].parent; f!=0; l=f, f=HT[f].parent)
       {
          if (HT[f].lchild == l)
          {
             cd[--start] = '0';
          }
          else
          {
             cd[--start] = '1';
          }
       }
       HC[i] = new char[n - start];
       strcpy(HC[i], &cd[start]);
    }
    delete [] cd;     // 释放工作空间
 #else
    // ---------无栈非递归遍历赫夫曼树, 求赫夫曼编码---------
    // ...
 #endif
 }131  void Select(HuffmanTree &HT, int count, int &min1, int &min2){
     int j=0;
     int j_index=0;
     Non_parent* n_parent=nullptr;
     n_parent=new Non_parent[count];
     for(int i=1;i<=count;i++){         
         if(HT[i].parent==0){
             n_parent[j].weight=HT[i].weight;
             n_parent[j].index=i;
             j++;
         }
     }
     int jMax=j;
     unsigned int temp=n_parent[0].weight;
     min1=n_parent[0].index;
     for(j=1;j<jMax;j++){                              //找出权重最小的节点
         if(n_parent[j].weight<temp){
             temp=n_parent[j].weight;
             min1=n_parent[j].index;
             j_index=j;
         }     
     }
     for(int i=j_index;i<jMax-1;i++){                  //去掉权重最小的节点
         n_parent[i]=n_parent[i+1];
     }
     temp=n_parent[0].weight;
     min2=n_parent[0].index;
     for(j=1;j<jMax-1;j++){                              //找出权重第二小的节点
         if(n_parent[j].weight<temp){
             temp=n_parent[j].weight;
             min2=n_parent[j].index;
         }     
     }
     delete[] n_parent;
     n_parent=nullptr;


 }
     

    




         


int main()
 {
    int i = 0;
    int cntLeaf = 0;
    int cntNode = 0;
 
   cout << "请输入叶子个数(正整数): ";
    cin >> cntLeaf;
    while (cntLeaf <= 0)
    {
       cout << "叶子个数不能为0, 请重新输入: ";
       cin >> cntLeaf;
    }
 
   cntNode = cntLeaf*2-1;
    char * pLetter = new char[cntLeaf];
    int * pWeight = new int[cntLeaf];
    for (i=0; i<cntLeaf; ++i)
    {
       cout << "请分别输入叶子结点的字符值和权值: ";
       cin >> pLetter[i] >> pWeight[i];
    }
 
   HuffmanTree HT = NULL;
    HuffmanCode HC = NULL;
    HuffmanCoding(HT, HC, pWeight, cntLeaf);
 
   cout << "Huffman树结构如下:\n";
    cout << setw(7) << "No."
       << setw(6+1) << "weight"
       << setw(6+1) << "parent"
       << setw(6+1) << "lchild"
       << setw(6+1) << "rchild"
       << '\n';
    for (i=0; i<cntNode; ++i)
    {
       cout << setw(6+1) << i+1 
         << setw(6+1) << HT[i+1].weight
          << setw(6+1) << HT[i+1].parent 
         << setw(6+1) << HT[i+1].lchild
          << setw(6+1) << HT[i+1].rchild
          << '\n';
    }
 
   cout << "\n各叶子结点的Huffman编码如下:\n";
    for (i=0; i<cntLeaf; ++i)
    {
       cout << pLetter[i] << ' ' << HC[i+1] << '\n';
    }
    
    for(int i=1;i<cntLeaf+1;i++){
        delete[] HC[i];
        HC[i]==nullptr;
    }
    
    delete[] HT;
    HT=nullptr;
    delete[] HC;
    HC=nullptr;
    delete[] pLetter;
    pLetter=nullptr;
    delete[] pWeight;
    pWeight=nullptr;
    
    return 0;
 }