void decode()
{
                                               
 cout<<"下面对根目录下文件codefile.txt中的字符进行译码"<<endl;
        FILE *codef,*txtfile;
        if((txtfile=fopen("Textfile.txt","w"))==NULL)
        {
                cout<<"不能打开文件"<<endl;
        }
        if ((codef=fopen("codefile.txt","r"))==NULL)
        {
                cout<<"不能打开文件"<<endl;
        }
   char *tbdc,*outext,i2;
   int io=0,i,m;
   unsigned long length=10000;
   tbdc=(char*)malloc(length*sizeof(char));
  fgets(tbdc,length,codef);
  outext=(char*)malloc(length*sizeof(char));
  
  m=2*n-1;
  for(i=0;*(tbdc+i)!='\0';i++)
  {
   i2=*(tbdc+i);
   if(HT[m].lchild==0)
   {
    *(outext+io)=*(z+m-1);
    io++;
    m=2*n-1;
    i--;
   }
   else if(i2=='0') m=HT[m].lchild;
   else if(i2=='1') m=HT[m].rchild;
  }
  *(outext+io)='\0';                           //这句不懂   那个加号干什么用的
  fputs(outext,txtfile);
  cout<<"译码完成"<<endl<<"内容写入根目录下的文件txtfile.txt中"<<endl<<endl;
  free(tbdc);
  free(outext);
        fclose(txtfile);
        fclose(codef);
}

C++没人。。。语法都差不多。。这个房间也一样