haffmandlg.cpp

霍夫曼编码解码

// HaffmanDlg.cpp : implementation file
//

#include "stdafx.h"
#include "Haffman.h"
#include "HaffmanDlg.h"
#include "fstream.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About

class CAboutDlg : public CDialog
{
public:
	CAboutDlg();

// Dialog Data
	//{{AFX_DATA(CAboutDlg)
	enum { IDD = IDD_ABOUTBOX };
	//}}AFX_DATA

	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CAboutDlg)
	protected:
	virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
	//}}AFX_VIRTUAL

// Implementation
protected:
	//{{AFX_MSG(CAboutDlg)
	//}}AFX_MSG
	DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
	//{{AFX_DATA_INIT(CAboutDlg)
	//}}AFX_DATA_INIT
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CAboutDlg)
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
	//{{AFX_MSG_MAP(CAboutDlg)
		// No message handlers
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CHaffmanDlg dialog

CHaffmanDlg::CHaffmanDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CHaffmanDlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CHaffmanDlg)
	m_character = _T("");
	m_result = _T("");
	//}}AFX_DATA_INIT
	// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);

	for(int i=0; i<100; i++)
	{
		m_weigh[i] = 0;
	}
	for(i=0; i<100; i++)
	{
		m_char[i] = '\0';
	}
}

void CHaffmanDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CHaffmanDlg)
	DDX_Control(pDX, IDC_LIST3, m_code);
	DDX_Text(pDX, IDC_CHAR, m_character);
	DDX_Text(pDX, IDC_EDIT, m_result);
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CHaffmanDlg, CDialog)
	//{{AFX_MSG_MAP(CHaffmanDlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDC_CODE, OnCode)
	ON_BN_CLICKED(IDC_DECODE, OnDecode)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CHaffmanDlg message handlers

BOOL CHaffmanDlg::OnInitDialog()
{
	CDialog::OnInitDialog();

	// Add "About..." menu item to system menu.

	// IDM_ABOUTBOX must be in the system command range.
	ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
	ASSERT(IDM_ABOUTBOX < 0xF000);

	CMenu* pSysMenu = GetSystemMenu(FALSE);
	if (pSysMenu != NULL)
	{
		CString strAboutMenu;
		strAboutMenu.LoadString(IDS_ABOUTBOX);
		if (!strAboutMenu.IsEmpty())
		{
			pSysMenu->AppendMenu(MF_SEPARATOR);
			pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
		}
	}

	// Set the icon for this dialog.  The framework does this automatically
	//  when the application's main window is not a dialog
	SetIcon(m_hIcon, TRUE);			// Set big icon
	SetIcon(m_hIcon, FALSE);		// Set small icon
	
	// TODO: Add extra initialization here
	
	return TRUE;  // return TRUE  unless you set the focus to a control
}

void CHaffmanDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
	if ((nID & 0xFFF0) == IDM_ABOUTBOX)
	{
		CAboutDlg dlgAbout;
		dlgAbout.DoModal();
	}
	else
	{
		CDialog::OnSysCommand(nID, lParam);
	}
}

// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.

void CHaffmanDlg::OnPaint() 
{
	if (IsIconic())
	{
		CPaintDC dc(this); // device context for painting

		SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);

		// Center icon in client rectangle
		int cxIcon = GetSystemMetrics(SM_CXICON);
		int cyIcon = GetSystemMetrics(SM_CYICON);
		CRect rect;
		GetClientRect(&rect);
		int x = (rect.Width() - cxIcon + 1) / 2;
		int y = (rect.Height() - cyIcon + 1) / 2;

		// Draw the icon
		dc.DrawIcon(x, y, m_hIcon);
	}
	else
	{
		CDialog::OnPaint();
	}
}

// The system calls this to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CHaffmanDlg::OnQueryDragIcon()
{
	return (HCURSOR) m_hIcon;
}

//编码
void CHaffmanDlg::OnCode() 
{
	// TODO: Add your control notification handler code here
	CFileDialog   dlg(TRUE,   "txt", NULL,   OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,   "Txt Files|*.txt");  //给文件名编辑框赋初值 
	CString filepath = "";
	if(dlg.DoModal() == IDOK)
	{
		filepath = dlg.GetPathName();
	}

	//读文件
	m_num = 0;
	m_allNum = 0;
	int flag;
	ifstream fin;
	fin.open(filepath);
	while(!fin.eof())
	{
		char c;
		fin>>c;
		m_allNum += 1;
		flag = -1;
		for(int i=1; i<=m_num; i++)
		{
			if(m_char[i] == c)
			{
				flag = i;
			}
		}

		if(flag==-1)
		{
			m_char[++m_num] = c;
		}
		else
		{
			m_weigh[flag] ++;
		}
	}	
	fin.close();
	//存储全部字符
	fin.open(filepath);
	fin>>m_all;
	fin.close();
	
	m_code.InsertString(0, "字符  编码");
	char code[100];
    
	huffman(tree,m_weigh, m_num);
	huffmancode(tree,code,m_num);
	tohuffmancode();

	UpdateData(false);
}

//解码
void CHaffmanDlg::OnDecode() 
{
	// TODO: Add your control notification handler code here
	int m = 2*m_num - 1;//树根结点
	int k=m;
	for(int i=0; i<m_character.GetLength(); i++)
	{			
		if(m_character.GetAt(i) == '0')
		{
			k=tree[k].lchild;
		}
		else
		{
			k=tree[k].rchild;
		}

		if(tree[k].lchild == 0 || tree[k].rchild == 0)
		{
			m_result += (CString)m_char[k];
			k=m;
		}
	}
	UpdateData(false);
}
//生成huffman树
void CHaffmanDlg::huffman(huftree tree[], int *w, int n)
{
	int m,i;
    if (n<=1) return;
    m=2*n-1;
	for (i=1;i<=n;i++)
    { tree[i].weight=w[i]; tree[i].parent=0;
     tree[i].lchild=0;    tree[i].rchild=0; }
    for (i=n+1;i<=m;i++)
    { tree[i].weight=0;   tree[i].parent=0;
     tree[i].lchild=0;   tree[i].rchild=0; }
    for (i=n+1;i<=m;i++)
    {  select(tree, i-1);
         tree[s1].parent=i;
         tree[s2].parent=i;
         tree[i].lchild=s1;
         tree[i].rchild=s2;     
         tree[i].weight =tree[s1]. weight+ tree[s2].weight;
     }
}
//找寻parent为0,权最小的两个节点
void CHaffmanDlg::select(huftree tree[], int k)
{
	int i;
	for (i=1;i<=k && tree[i].parent!=0 ;i++); s1=i;
	for (i=1;i<=k;i++)
		if (tree[i].parent==0 && tree[i].weight<tree[s1].weight) s1=i;
	for (i=1; i<=k ; i++)
		if (tree[i].parent==0 && i!=s1) break; s2=i;
	for (i=1;i<=k;i++)
		if ( tree[i].parent==0 && i!=s1 && tree[i].weight<tree[s2].weight) s2=i;
}

//编码
void CHaffmanDlg::huffmancode(huftree tree[], char code[], int n)
{
	int start,c,i,f;
	code[n]='\0';
	CString str;
	for(i=1;i<=n;i++)
	{
		start=n;
		for(c=i,f=tree[i].parent;f!=0;c=f,f=tree[f].parent)
		{
			if(tree[f].lchild==c)
				code[--start]='0';
			else 
				code[--start]='1';
		}
		strcpy(hc[i],&code[start]);
		CString str1,str ="";
		str +=(CString)m_char[i]+"       ";
		str1.Format(hc[i]);
		str +=str1;
		m_code.InsertString(i, str);
	}	
}

//针对字符编码
void CHaffmanDlg::tohuffmancode()
{
	CString str;
	for(int i=0; i<m_allNum-1; i++)
	{
		for(int j=1; j<=m_num; j++)
		{
			if(m_all[i] == m_char[j])
			{
				str.Format(hc[j]);
			}
		}
		m_character += str;
	}
}