怎么利用C++實現赫夫曼編碼譯碼器

本篇內容主要講解“怎么利用C++實現赫夫曼編碼譯碼器”，感興趣的朋友不妨來看看。本文介紹的方法操作簡單快捷，實用性強。下面就讓小編來帶大家學習“怎么利用C++實現赫夫曼編碼譯碼器”吧!

首先，我們來看看main函數：

void main()  {          char choice=' ';          while(choice!='q')          {       cout<<"\n******************************"<                cout<<" 歡迎使用赫夫曼編碼譯碼系統"<                cout<<"******************************"<                cout<<"(1)要初始化赫夫曼鏈表請輸入'i'"<                cout<<"(2)輸入要編碼的字符'w'"<                cout<<"(3)要編碼請輸入'e'"<                cout<<"(4)要譯碼請輸入'd'"<                cout<<"(5)要打印編碼請輸入'p'"<                cout<<"(6)要打印赫夫曼樹請輸入't'"<                cout<<"(7)要離開請輸入'q'"<                if(flag==0)cout<<"\n請先初始化赫夫曼鏈表,輸入'i'"<                cin>>choice;                   switch(choice)                   {                   case 'i':                                  Initialization();                                  break;                   case 'w':                                  InputCode();                                  break;                   case 'e':                                  Encoding();                                  break;                   case 'd':                                  Decoding();                                  break;                   case 'p':                                  Code_printing();                                  break;                   case 't':                                      Tree_printing(HT,2*n-1);                                      break;                   case 'q':                                  break;                   default:                                  cout<<"input error"<                 }            }         free(z);         free(w);         free(HT);  }

這個函數主要就是和用戶交互使用。這個過程我用switch case 來實現，你們也可以選擇其他的方式實現如if else ，這個就個人愛好選擇。下面我們來看看初始化赫夫曼樹的函數Initialization（）。
<n<<"個字符(字符型)\n注意:必須以回車結束："<<endl;
<i+1<<"個字符:"<<endl;
<n<<"個權值(\n注意:必須以回車結束)："<<endl;
<endl<<"第"<<i+1<<"個字符的權值:";

void Initialization()  {          flag=1;          int num;          int num2;          cout<<"下面初始化赫夫曼鏈表"<        cin>>num;          n=num;          w=(int*)malloc(n*sizeof(int));          z=(char*)malloc(n*sizeof(char));          cout<<"\n請依次輸入"<        char base[2];          for(i=0;i   {          cout<<"第"<        gets(base);//這個地方有點小小的問題          *(z+i)=*base;          }          for(i=0;i<=n-1;i++)          {                  cout<        }          cout<<"\n請依次輸入"<        for(i=0;i<=n-1;i++)          {           cout<         cin>>num2;           *(w+i)=num2;     }          HuffmanCoding(HT,HC,w,n);  //------------------------打印編碼-------------------------------------------          cout<<"字符對應的編碼為:"<        for(i=1;i<=n;i++)          {                  //cout<<"字符"<<*(z+i-1)<<"的編碼";                  puts(HC[i]);          }  //--------------------------將赫夫曼編碼寫入文件------------------------          cout<<"下面將赫夫曼編碼寫入文件"<            FILE *hfmTree;          char r[]={' ','\0'};                 if((hfmTree=fopen("hfmTree.txt","w"))==NULL)     {     cout<<"can not open file"<   return;     }            fputs(z,hfmTree);          for(i=0;i        {           fprintf(hfmTree,"%6d",*(w+i));           fputs(r,hfmTree);     }          for(i=1;i<=n;i++)          {           fputs(HC[i],hfmTree);           fputs(r,hfmTree);          }          fclose(hfmTree);          cout<<"已將字符與對應編碼寫入根目錄下文件hfmTree.txt中"<}

上述代碼中有個小問題，已經用紅色標示，這個地方獲取數據的時候有一次是沒有輸入就直接執行的。這個疑問我一直都沒想通。初始化的結果放入hfmTree.txt的文件中。

下面來看看輸入要編碼的字符的函數InputCode（）

void InputCode()  {      //cout<<"請輸入你想要編碼的字符"<    FILE *tobetran;      char str[100];      if((tobetran=fopen("tobetran.txt","w"))==NULL)      {          cout<<"不能打開文件"<        return;      }      cout<<"請輸入你想要編碼的字符"<    cin>>str;      fputs(str,tobetran);      cout<<"獲取報文成功"<    fclose(tobetran);  }

這個函數里我也碰到了一個問題，cin>>str;部分一開始的時候，我是用gets代替的，不過問題就是用gets我不用輸入就能直接執行完函數。這個郁悶啊。

下面來看看赫夫曼編碼/譯碼器函數

//---------------------編碼函數---------------------------------  void Encoding()  {          cout<<"下面對目錄下文件tobetran.txt中的字符進行編碼"<            FILE *tobetran,*codefile;            if((tobetran=fopen("tobetran.txt","rb"))==NULL)          {                  cout<<"不能打開文件"<        }          if((codefile=fopen("codefile.txt","wb"))==NULL)          {                  cout<<"不能打開文件"<        }            char *tran;          i=99;          tran=(char*)malloc(100*sizeof(char));            while(i==99)          {                  if(fgets(tran,100,tobetran)==NULL)                  {                          cout<<"不能打開文件"<                        break;                  }                  for(i=0;*(tran+i)!='\0';i++)                  {                          for(j=0;j<=n;j++)                          {                                  if(*(z+j-1)==*(tran+i))                                  {                                    fputs(HC[j],codefile);                                    if(j>n)                                    {                                     cout<<"字符錯誤，無法編碼!"<                                   break;                                    }                                  }                          }                  }          }          cout<<"編碼工作完成"<        fclose(tobetran);          fclose(codefile);          free(tran);  }    //-----------------譯碼函數---------------------------------  void Decoding()  {  cout<<"下面對根目錄下文件codefile.txt中的字符進行譯碼"<        FILE *codef,*txtfile;          if((txtfile=fopen("\\Textfile.txt","w"))==NULL)          {                  cout<<"不能打開文件"<        }  //txtfile=fopen("Textfile.txt","w");          if ((codef=fopen("codefile.txt","r"))==NULL)          {                  cout<<"不能打開文件"<        }  //codef=fopen("codefile.txt","r");     char *work,*work2,i2;  int i4=0,i,i3;          unsigned long length=10000;          work=(char*)malloc(length*sizeof(char));  fgets(work,length,codef);  work2=(char*)malloc(length*sizeof(char));  i3=2*n-1;  for(i=0;*(work+i)!='\0';i++)  {     i2=*(work+i);     if(HT[i3].lchild==0)      {      *(work2+i4)=*(z+i3-1);      i4++;      i3=2*n-1;      i--;     }     else if(i2=='0') i3=HT[i3].lchild;     else if(i2=='1') i3=HT[i3].rchild;  }  *(work2+i4)='\0';  fputs(work2,txtfile);  cout<<"譯碼完成"<free(work);  free(work2);          fclose(txtfile);          fclose(codef);    }

整個赫夫曼編碼/譯碼器實現過程也就這樣了。

到此，相信大家對“怎么利用C++實現赫夫曼編碼譯碼器”有了更深的了解，不妨來實際操作一番吧！這里是億速云網站，更多相關內容可以進入相關頻道進行查詢，關注我們，繼續學習！