CAVALIERS SUR UN ÉCHIQUIER

//http://pabbati.free.fr/
#include <windows.h>
#include <time.h>
#include <stdlib.h>

#pragma warn -sig
//#define CarresMagique
#define MAX 8
HINSTANCE hInst;
HWND hwnd;
char szAppName[]="Chevaux";
PAINTSTRUCT ps;
MSG         msg ;
WNDCLASS    wndclass ;
HACCEL      hAccel;
unsigned char c[MAX][MAX];
unsigned char a,b,x,y,z,xx,yy,i,j;
char s[50];
HDC hdc;
SIZE size={16,16};
int taille;

unsigned char ok(unsigned char i,unsigned char j)
{
 return ((i<MAX)&&(j<MAX)&&(c[i][j]==0));
}

#define X0 x+2,y-1
#define X1 x+2,y+1
#define X2 x-2,y-1
#define X3 x-2,y+1
#define X4 x+1,y-2
#define X5 x+1,y+2
#define X6 x-1,y-2
#define X7 x-1,y+2
void essai(unsigned char c,unsigned char x,unsigned char y)
{
 if(b&c)
 {
  b-=c;
  if(ok(x,y))
  {
	unsigned char k=ok(X0)+ok(X1)+ok(X2)+ok(X3)+ok(X4)+ok(X5)+ok(X6)+ok(X7);
	if(k<a)
	{
	 xx=x;
	 yy=y;
	 a=k;
	}
  }
 }
}

BOOL choix()
{
 a=9;
 b=0xFF;
 do
 {
  switch(random(8))
  {           
	case 0:essai(0x01,X0);break;
	case 1:essai(0x02,X1);break;
	case 2:essai(0x04,X2);break;
	case 3:essai(0x08,X3);break;
	case 4:essai(0x10,X4);break;
	case 5:essai(0x20,X5);break;
	case 6:essai(0x40,X6);break;
	case 7:essai(0x80,X7);break;
  }
 }
 while(b);
 return (a<9);
}

void CaretPos()
{
 unsigned char i,j;
 for(i=0;i<MAX;i++)
 for(j=0;j<MAX;j++)
 if(c[i][j]==z)
 {
  SetCaretPos(10+taille*i,5+taille*j);
  return;
 }
}

void init(char k)
{
 static unsigned char i=0,j=0;
 memset(c,0,sizeof(c));
 if(k)
 {
  if(k<2)if(++i>MAX-1){i=0;if(++j>MAX-1)j=0;}
  xx=i;
  yy=j;
 }
 else
 {
  xx=random(MAX);
  yy=random(MAX);
 }
 z=0;
}

#ifdef CarresMagique
BOOL CarreMagique()
{
	unsigned char i,j;
	UINT r1,r2,r3,n=0;
	for(i=0;i<MAX;i++)n+=c[i][i];
	r3=0;
	for(i=0;i<MAX;i++)
	{
	 r3+=c[i][MAX-i-1];
	 r1=r2=0;
	 for(j=0;j<MAX;j++){r1+=c[i][j];r2+=c[j][i];}
	 if((r1!=n)||(r2!=n))return FALSE;
	}
	if(r3!=n)return FALSE;
	return TRUE;
}
#endif

void cherche(char k=0)
{
 unsigned compte=0;
 encore:
 init(k);
 do
 {
  x=xx;y=yy;
  c[x][y]=++z;
 }
 while(choix());
 if(z!=MAX*MAX)
 {
  if(compte++<50)goto encore;
  z=1;
  CaretPos();
  InvalidateRect(hwnd,NULL,TRUE);
  MessageBox(hwnd,"Résultat non trouvé",szAppName,MB_ICONEXCLAMATION);
 }
 z=1;
 CaretPos();
#ifdef CarresMagique
 if(CarreMagique())
 {
  InvalidateRect(hwnd,NULL,TRUE);
  MessageBox(hwnd,"C'est un carré magique",szAppName,MB_ICONEXCLAMATION);
 }
#endif
}

long FAR PASCAL WndProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam)
{
 switch (message)
 {
  case WM_SETCURSOR:SetCursor(LoadCursor(NULL,IDC_ARROW));return TRUE;
  case WM_PAINT:
	hdc=BeginPaint(hwnd,&ps);
	for(i=0;i<MAX;i++)
	{
	 for(j=0;j<MAX;j++)
	 {
//	  if(c[i][j]==z)CaretPos(i,j);
	  wsprintf(s,"%02u",(int)c[i][j]);
	  TextOut(ps.hdc,10+taille*i,5+taille*j,s,lstrlen(s));
	 }
	}
	EndPaint(hwnd,&ps);
  break;
  case WM_LBUTTONDOWN:PostMessage(hwnd,WM_KEYDOWN,VK_RETURN,0);break;
  case WM_MBUTTONDOWN:PostMessage(hwnd,WM_KEYDOWN,VK_TAB,0);break;
  case WM_RBUTTONDOWN:PostMessage(hwnd,WM_KEYDOWN,VK_SPACE,0);break;
  case WM_KEYDOWN:
	switch(LOWORD(wParam))
	{
	 case VK_UP:
	 case VK_RIGHT:if(++z>MAX*MAX)z=1;CaretPos();break;
	 case VK_DOWN:
	 case VK_LEFT:if(--z==0)z=MAX*MAX;CaretPos();break;
	 case VK_ESCAPE:PostMessage(hwnd,WM_CLOSE,0,0);break;
	 case VK_F1:MessageBox(hwnd,"Touches Droite, Gauche, Haut, Bas...\n\nTabulation, Entrée, Espace...",szAppName,MB_ICONINFORMATION);break;
	 case VK_F2:
	 case VK_RETURN:cherche();InvalidateRect(hwnd,NULL,TRUE);break;
	 case VK_F3:
	 case VK_TAB:cherche(1);InvalidateRect(hwnd,NULL,TRUE);break;
	 case VK_F4:
	 case VK_SPACE:cherche(2);InvalidateRect(hwnd,NULL,TRUE);break;
	}
  break;
  case WM_KILLFOCUS:DestroyCaret();break;
  case WM_SETFOCUS:CreateCaret(hwnd,NULL,size.cx,size.cy);ShowCaret(hwnd);break;
  case WM_DESTROY:PostQuitMessage(0);break;
  case WM_CREATE:
	RemoveMenu(GetSystemMenu(hwnd,FALSE),2,MF_BYPOSITION);
	RemoveMenu(GetSystemMenu(hwnd,FALSE),3,MF_BYPOSITION);
	hdc=GetDC(hwnd);
	GetTextExtentPoint32(hdc,"00",2,&size);
	ReleaseDC(hwnd,hdc);
	size.cy>size.cx?taille=size.cy:taille=size.cx;
	taille+=6;
	SetWindowPos(hwnd,HWND_TOP,0,0,12+taille*MAX+2*GetSystemMetrics(SM_CXFRAME),5+taille*MAX+GetSystemMetrics(SM_CYCAPTION)+2*GetSystemMetrics(SM_CYFRAME),SWP_NOMOVE|SWP_NOREDRAW|SWP_NOZORDER);
	PostMessage(hwnd,WM_KEYDOWN,VK_RETURN,0);
  break;
  default:return DefWindowProc(hwnd,message,wParam,lParam) ;
 }
 return 0;
}

#pragma argsused
int PASCAL WinMain (HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpszCmd,int nCmdShow)
{
 randomize();
 hInst=hInstance;
  wndclass.style         = CS_HREDRAW | CS_VREDRAW ;
  wndclass.lpfnWndProc   = (WNDPROC)WndProc ;
  wndclass.cbClsExtra    = 0 ;
  wndclass.cbWndExtra    = 0 ;
  wndclass.hInstance     = hInst;
  wndclass.hIcon         = LoadIcon(hInst,MAKEINTRESOURCE(1));
  wndclass.hCursor       = LoadCursor(NULL,IDC_ARROW);
  wndclass.hbrBackground = (HBRUSH)GetStockObject(LTGRAY_BRUSH);
  wndclass.lpszMenuName  = MAKEINTRESOURCE(1);
  wndclass.lpszClassName = szAppName;
  RegisterClass (&wndclass) ;

  hwnd = CreateWindow (
	szAppName,
	szAppName,
	WS_MINIMIZEBOX|WS_SYSMENU|WS_CAPTION|WS_THICKFRAME,
	CW_USEDEFAULT,
	CW_USEDEFAULT,
	CW_USEDEFAULT,
	CW_USEDEFAULT,
	NULL,
	NULL,
	hInst,
	NULL);


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

// hAccel = LoadAccelerators( hInstance,MAKEINTRESOURCE(1));

 while (GetMessage (&msg, NULL, 0, 0))
 {
//  if ( !TranslateAccelerator( hwnd, hAccel, &msg ))
  {
	TranslateMessage (&msg) ;
	DispatchMessage (&msg) ;
  }
 }
// UnregisterClass(szAppName,hInstance);
 return msg.wParam ;
}