关于数据结构:构建赫夫曼树及求赫夫曼编码从叶子到根逆向

#include<iostream>#include<string.h>using namespace std;typedef struct{    int weight;    int parent,lchild,rchild;}HTNode,*HuffmanTree;void Select(HuffmanTree HT,int len,int &s1,int &s2){    int i,min1=0x3f3f3f3f,min2=0x3f3f3f3f;    for(i=1;i<=len;i++){        if(HT[i].weight<min1&&HT[i].parent==0){            min1=HT[i].weight;            s1=i;        }        }    int temp=HT[s1].weight;    HT[s1].weight=0x3f3f3f3f;    for(i=1;i<=len;i++){        if(HT[i].weight<min2&&HT[i].parent==0){            min2=HT[i].weight;            s2=i;        }    }    HT[s1].weight=temp;}//结构赫夫曼树void CreatHuffmanTree(HuffmanTree &HT,int n){    int m,s1,s2,i;    if(n<=1) return;    m=2*n-1;    HT=new HTNode[m+1];          for(i=1;i<=m;++i){         HT[i].parent=0;          HT[i].lchild=0;          HT[i].rchild=0;     }    cout<<"叶子结点权值：";    for(i=1;i<=n;++i)                 cin>>HT[i].weight;      for(i=n+1;i<=m;++i){        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;         }                                                 }     typedef char **HuffmanCode; //赫夫曼编码  void CreatHuffmanCode(HuffmanTree HT,HuffmanCode &HC,int n){    int i,start,c,f;    HC=new char*[n+1];                                     char *cd=new char[n];                                cd[n-1]='\0';                                        for(i=1;i<=n;++i){                                                          start=n-1;                                          c=i;         f=HT[i].parent;                                     while(f!=0){                                                      --start;                                          if(HT[f].lchild==c)                  cd[start]='0';                                    else                 cd[start]='1';                                 c=f;             f=HT[f].parent;                             }                                                         HC[i]=new char[n-start];                             strcpy(HC[i], &cd[start]);                       }    delete cd;                                        }                                                    void show(HuffmanTree HT,HuffmanCode HC,int n){    for(int i=1;i<=n;i++)        cout<<HT[i].weight<<"赫夫曼编码为："<<HC[i]<<endl;}                                                int main(){    HuffmanTree HT;    int n;    cout<<"叶子结点个数：";    cin>>n;    CreatHuffmanTree(HT,n);    HuffmanCode HC;    CreatHuffmanCode(HT,HC,n);    show(HT,HC,n);}