Question

c++问题，知道的请进

请问如下程序为什么计算结果不正确！？
#include<iostream>
#include<fstream>

using namespace std;

int main()
{
FILE *p;
if( (p=fopen("123.txt","w+")) == NULL)
{
printf("can not create file 123.txt\n");
exit(0);
}
int a,b,c,d,e,f;
int aa=0,bb=0,cc=0,dd=0,ee=0,ff=0;
ifstream login_file("1.txt");
while(login_file)
{
login_file>>a>>b>>c>>d>>e>>f;
if(a!=aa && b!=bb && c!=cc && d!=dd && e!=ee && f!=ff)d
{
fprintf(p,"\n%02d %02d %02d %02d %02d %02d",a,b,c,d,e,f);
aa=a;
bb=b;
cc=c;
dd=d;
ee=e;
ff=f;
}
}
fclose(p);
return 0;
}

Answer 1

Windows API程序：
#include <windows.h>

LONG WINAPI WndProc (HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpszCmdLine, int nCmdShow)
{
WNDCLASS wc;
HWND hwnd;
MSG msg;

wc.style = 0; // Class style
wc.lpfnWndProc = (WNDPROC) WndProc; // Window procedure address
wc.cbClsExtra = 0; // Class extra bytes
wc.cbWndExtra = 0; // Window extra bytes
wc.hInstance = hInstance; // Instance handle
wc.hIcon = LoadIcon (NULL, IDI_WINLOGO); // Icon handle
wc.hCursor = LoadCursor (NULL, IDC_ARROW); // Cursor handle
wc.hbrBackground = (HBRUSH) (COLOR_WINDOW + 1); // Background color
wc.lpszMenuName = NULL; // Menu name
wc.lpszClassName = "MyWndClass"; // WNDCLASS name

RegisterClass (&wc);

hwnd = CreateWindow (
"MyWndClass", // WNDCLASS name
"SDK Application", // Window title
WS_OVERLAPPEDWINDOW, // Window style
CW_USEDEFAULT, // Horizontal position
CW_USEDEFAULT, // Vertical position
CW_USEDEFAULT, // Initial width
CW_USEDEFAULT, // Initial height
HWND_DESKTOP, // Handle of parent window
NULL, // Menu handle
hInstance, // Application's instance handle
NULL // Window-creation data
);

ShowWindow (hwnd, nCmdShow);
UpdateWindow (hwnd);

while (GetMessage (&msg, NULL, 0, 0)) {
TranslateMessage (&msg);
DispatchMessage (&msg);
}
return msg.wParam;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
LPARAM lParam)
{
PAINTSTRUCT ps;
HDC hdc;

switch (message) {

case WM_PAINT:
hdc = BeginPaint (hwnd, &ps);
Ellipse (hdc, 0, 0, 200, 100);
EndPaint (hwnd, &ps);
return 0;

case WM_DESTROY:
PostQuitMessage (0);
return 0;
}
return DefWindowProc (hwnd, message, wParam, lParam);
}

简单的MFC程序
Hello.h
class CMyApp : public CWinApp
{
public:
virtual BOOL InitInstance ();
};

class CMainWindow : public CFrameWnd
{
public:
CMainWindow ();

protected:
afx_msg void OnPaint ();
DECLARE_MESSAGE_MAP ()
};

Hello.cpp
#include <afxwin.h>
#include "Hello.h"

CMyApp myApp;

/////////////////////////////////////////////////////////////////////////
// CMyApp member functions

BOOL CMyApp::InitInstance ()
{
m_pMainWnd = new CMainWindow;

m_pMainWnd->ShowWindow (m_nCmdShow);
m_pMainWnd->UpdateWindow ();
return TRUE;
}

/////////////////////////////////////////////////////////////////////////
// CMainWindow message map and member functions

BEGIN_MESSAGE_MAP (CMainWindow, CFrameWnd)
ON_WM_PAINT ()
END_MESSAGE_MAP ()

CMainWindow::CMainWindow ()
{
Create (NULL, _T ("The Hello Application"));
}

void CMainWindow::OnPaint ()
{
CPaintDC dc (this);

CRect rect;
GetClientRect (&rect);

dc.DrawText (_T ("Hello, MFC"), -1, &rect,
DT_SINGLELINE ¦ DT_CENTER ¦ DT_VCENTER);
}