vc抽奖程序当抽奖人数大于140以上就常出现内存读错误码，请高手帮忙。

[canlan123]

这是代码
原程序我已经通过附件的方式上传了。
#include "stdafx.h"
#include "gift.h"
#include "giftDlg.h"

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

/////////////////////////////////////////////////////////////////////////////
// CGiftDlg dialog

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

void CGiftDlg::DoDataExchange(CDataExchange* pDX)
{
CDialog::DoDataExchange(pDX);
//{{AFX_DATA_MAP(CGiftDlg)
DDX_Control(pDX, IDOK, m_btgo);//新代码
DDX_Text(pDX, IDC_STATIC_CODE2, m_code);//新代码
DDX_Text(pDX, IDC_STATIC_MSG, m_msg);//新代码
//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CGiftDlg, CDialog)
//{{AFX_MSG_MAP(CGiftDlg)
ON_WM_PAINT()
ON_WM_QUERYDRAGICON()
ON_WM_TIMER()//新代码
//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CGiftDlg message handlers

BOOL CGiftDlg::OnInitDialog()
{
CDialog::OnInitDialog();
InitData();//新代码
bstart=false;//新代码
// 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
m_msg.Format ("现有评课人数：%d",totalid);//新代码
UpdateData(FALSE);//新代码
return TRUE; // return TRUE unless you set the focus to a control
}

// 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 CGiftDlg::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);//新代码
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 CGiftDlg::OnQueryDragIcon()
{
return (HCURSOR) m_hIcon;
}
//以下都是新加代码
void CGiftDlg::OnOK()
{
// TODO: Add extra validation here
if(bstart)
{
KillTimer(1);
bstart=false;
m_msg.Format ("现有评课人数：%d",totalid-1);
m_code.Format ("抽出的号码：%s 姓名：%s",code[data[ptr]],name[data[ptr]]);
//AfxMessageBox(m_code);
ReSetData();//剔除抽出的号码,重新打乱
if(totalid<1)
{
m_btgo.EnableWindow (FALSE);
}
m_btgo.SetWindowText ("开始");
}
else
{
SetTimer(1, 10,NULL);
bstart=true;
m_msg.Format ("按停止键抽一个奖");
m_btgo.SetWindowText ("停止");
}
UpdateData(FALSE);
//CDialog::OnOK();
}

void CGiftDlg::OnTimer(UINT nIDEvent)
{
// TODO: Add your message handler code here and/or call default
m_code.Format ("现在的号码：%s",code[data[ptr]]);
UpdateData(FALSE);
ptr++;
ptr%=totalid;
CDialog::OnTimer(nIDEvent);
}



int CGiftDlg::InitData()
{

FILE * fp=fopen("id.txt","r");
ptr=0;
totalid=1;
if (fp==NULL)
{
return 0;
}
char buf[800];
int line=0;
while(!feof(fp))
{
char *p=fgets(buf,800,fp);
if (p!=NULL)
{
name[line]=(char*)malloc(800);
code[line]=(char*)malloc(800);
memset(code[line],0,800);
memset(name[line],0,800);

int flag=0;
for(int i=0;i<800&&buf[i]!='\0';i++)
{
if((buf[i]!=',' )&& (flag==0))
{
code[line][i]=buf[i];
}
else if(flag==0)
{
flag=i;
}
else if((buf[i]!=',' )&& (flag!=0))
{
name[line][i-flag-1]=buf[i];
}
}
TRACE("%s-%s",code[line],name[line]);
memset(buf,0,800);
line++;
}
}
fclose(fp);
for(int j=0;j<line;j++)
{
data[j]=j;
}
for(int i=0;i<line;i++)
{
int pos=rand()%(line-i)+i;
int temp=data[i];
data[i]=data[pos];
data[pos]=temp;
TRACE("%d",data[i]);
}
totalid=line;
return 1;
}

int CGiftDlg::ReSetData()
{
//ptr剔除,与最后一个交换,然后释放内存
int line=totalid;
int temp=data[ptr];
data[ptr]=data[line-1];
data[line-1]=temp;
//AfxMessageBox(name[data[line-1]]);
free(code[data[line-1]]);
free(name[data[line-1]]);
totalid--;
line--;
ptr=0;
for(int i=0;i<line;i++)//重新打乱
{
int pos=rand()%(line-i)+i;
int temp=data[i];
data[i]=data[pos];
data[pos]=temp;
TRACE("%d",data[i]);
}


return 1;
}

int CGiftDlg::FreeMem()
{
int line=totalid;
for(int i=0;i<line;i++)
{
free(code[i]);
free(name[i]);
}
return 1;
}