C++博客-VC++ C++ C# Algorithm

用递规方法解决Hanoi问题

大熊猫 — Thu, 15 Mar 2007 08:46:00 GMT

void move( int number, char from, char rely, char to)
{
     if (number == 1 )
     {
        printf( " Move a disk from %c to %c\n " ,from,to);
         return ;
    }
    move(number - 1 ,from,to,rely);
    move( 1 ,from,rely,to);
    move(number - 1 ,rely,from,to);
}

int _tmain( int argc, _TCHAR * argv[])
{
    move( 3 , ' A ' , ' B ' , ' C ' );
    ::system( " pause " );
     return 0 ;
}

大熊猫 2007-03-15 16:46 发表评论

插入排序

大熊猫 — Thu, 15 Mar 2007 08:32:00 GMT

1 int A[ 10 ] = { 1 , 2 , 5 , 7 , 3 , 14 , 78 , 25 , 11 , 14 } ;
2 void InsertSort( int a[], int size)
3 {
4      for ( int i = 1 ; i < size; i ++ )
5      {
6          int key = a[i];
7          int j = i - 1 ;
8          while (a[j] > key && j >= 0 )
9          {
10             a[j + 1 ] = a[j];
11             j -- ;
12         }
13         a[j + 1 ] = key;
14     }
15 }
16
17 int _tmain( int argc, _TCHAR * argv[])
18 {
19
20     InsertSort(A, sizeof (A) / sizeof (A[ 0 ]));
21      for ( int i = 0 ; i < 10 ; i ++ )
22      {
23         printf( " %d\n " ,A[i]);
24     }
25     ::system( " pause " );
26      return 0 ;
27 }
28

大熊猫 2007-03-15 16:32 发表评论

SDL游戏编程(8)鼠标事件

大熊猫 — Mon, 12 Mar 2007 12:10:00 GMT

很多游戏都是用鼠标控制的，所以说处理鼠标事件也是非常重要的，鼠标事件和键盘事件处理方式差的不太多，所以我就直接给出了一个小程序，该程序把窗口一分为二，当在左半部分移动时，左面部分就变绿色，右面部分变黑色，在右半部分移动时，该部分就变蓝色，左半部分就变成了黑色，当鼠标左击时，对应的部分将会变红色。

#include " SDL.h "
#include " SDL_ttf.h "
SDL_Surface * screen = NULL;

TTF_Font * font = NULL;
// screen to show on window
const int SCREEN_BPP = 32 ;

int main( int argc, char * args[] )
{
     // Start SDL
     bool quit = false ;
    SDL_Rect rectLeft;
    SDL_Rect rectRight;
    rectLeft.x = 0 ;
    rectLeft.y = 0 ;
    rectLeft.w = 320 ;
    rectLeft.h = 480 ;
    rectRight.x = 320 ;
    rectRight.y = 0 ;
    rectRight.w = 640 ;
    rectRight.h = 480 ;
    SDL_Init( SDL_INIT_EVERYTHING );
     if (TTF_Init() ==- 1 )
         return false ;

    screen = SDL_SetVideoMode( 600 , 480 , SCREEN_BPP, SDL_SWSURFACE );
     if (screen == NULL)
         return false ;

    Uint32 colorBlue = SDL_MapRGB(screen -> format, 0 , 0 , 255 );
    Uint32 colorGreen = SDL_MapRGB(screen -> format, 0 , 255 , 0 );
    Uint32 colorRed = SDL_MapRGB(screen -> format, 255 , 0 , 0 );
    Uint32 colorBlack = SDL_MapRGB(screen -> format, 0 , 0 , 0 );
    SDL_Event event ;
     while ( ! quit)
     {
         if (SDL_PollEvent( & event ))
         {
             if ( event .type == SDL_MOUSEMOTION)
             {
                Uint16 x = event .motion.x;
                Uint16 y = event .motion.y;

                 if (x > 0 && x < 320 && y > 0 && y < 480 )
                 {
                    SDL_FillRect(screen, & rectLeft,colorBlue);
                    SDL_FillRect(screen, & rectRight,colorBlack);
                }
                 if (x > 320 && x < 640 && y > 0 && y < 480 )
                 {
                    SDL_FillRect(screen, & rectRight,colorGreen);
                    SDL_FillRect(screen, & rectLeft,colorBlack);
                }
            }
             if ( event .type == SDL_MOUSEBUTTONDOWN)
             {
                Uint16 x = event .motion.x;
                Uint16 y = event .motion.y;
                 if ( event .button.button == SDL_BUTTON_LEFT)
                 {
                     if (x > 0 && x < 320 && y > 0 && y < 480 )
                     {
                        SDL_FillRect(screen, & rectLeft,colorRed);
                    }
                     if (x > 320 && x < 640 && y > 0 && y < 480 )
                     {
                        SDL_FillRect(screen, & rectRight,colorRed);
                    }
                }
            }
             if ( event .type == SDL_QUIT)
                quit = true ;
        }
         if (SDL_Flip(screen) == - 1 )
         {
             return false ;
        }
    }
    SDL_FreeSurface(screen);
    SDL_Quit();

     return 0 ;
}

大熊猫 2007-03-12 20:10 发表评论

SDL游戏编程(7)键盘事件

大熊猫 — Mon, 12 Mar 2007 11:27:00 GMT

这次我们看看如何在SDL中处理键盘事件，每次事件发生以后，有关事件的所有信息都存储在SDL_Event类型的变量当中，查查手册我们可以知道，实际SDL_Event是一个联合体。
typedef union{
Uint8 type;
SDL_ActiveEvent active;
SDL_KeyboardEvent key;
SDL_MouseMotionEvent motion;
SDL_MouseButtonEvent button;
SDL_JoyAxisEvent jaxis;
SDL_JoyBallEvent jball;
SDL_JoyHatEvent jhat;
SDL_JoyButtonEvent jbutton;
SDL_ResizeEvent resize;
SDL_ExposeEvent expose;
SDL_QuitEvent quit;
SDL_UserEvent user;
SDL_SywWMEvent syswm;
} SDL_Event;
当发生键盘事件时，key变量就是有效的。
typedef struct{
Uint8 type;
Uint8 state;
SDL_keysym keysym;
} SDL_KeyboardEvent;
key变量是一个结构体，其中keysym成员包含了按键信息。
typedef struct{
Uint8 scancode;
SDLKey sym;
SDLMod mod;
Uint16 unicode;
} SDL_keysym;
在keysym的成员当中，sym记录按键所对应的虚拟键。
比如说向上就是SDLK_UP；向下就是SDLK_DOWN；大家可以自己去查手册。

下面就看一个处理键盘消息的实例吧。
该例子中，我们一旦发现有上下左右四个键被按下，就马上在屏幕上显示相对应的消息，这里用到了扩展类库SDL_TTF，如有不清楚的，参考一下前面的几篇文章。

#include "SDL.h"
#include "SDL_ttf.h"
SDL_Surface *screen=NULL;
SDL_Surface *up=NULL;
SDL_Surface *down=NULL;
SDL_Surface *left=NULL;
SDL_Surface *right=NULL;
SDL_Surface *message=NULL;
TTF_Font *font=NULL;
//screen to show on window
const int SCREEN_BPP=32;
SDL_Color textColor={255,255,255};

int main( int argc, char* args[] )
{
    //Start SDL
    bool quit=false;
    SDL_Init( SDL_INIT_EVERYTHING );
    if(TTF_Init()==-1)
        return false;

    screen = SDL_SetVideoMode( 600, 480, SCREEN_BPP, SDL_SWSURFACE );
    if(screen==NULL)
        return false;
    font=TTF_OpenFont("tahoma.ttf",28);
    up = TTF_RenderText_Solid( font, "Up was pressed.", textColor );
    down = TTF_RenderText_Solid( font, "Down was pressed.", textColor );
    left = TTF_RenderText_Solid( font, "Left was pressed", textColor );
    right = TTF_RenderText_Solid( font, "Right was pressed", textColor );
    SDL_Event event;
    while(!quit)
    {
        if(SDL_PollEvent(&event))
        {
            if(event.type == SDL_KEYDOWN)
            {
                switch(event.key.keysym.sym)
                {
                    case SDLK_UP: message=up;break;
                    case SDLK_DOWN: message=down;break;
                    case SDLK_LEFT: message=left;break;
                    case SDLK_RIGHT: message=right;break;
                }
            }
            if(event.type == SDL_QUIT)
                quit=true;
        }
        if(message != NULL)
        {
            Uint32 colorVal=SDL_MapRGB(screen->format,0,0,0);
            SDL_FillRect(screen, &screen->clip_rect,colorVal);
            SDL_BlitSurface(message,NULL,screen,NULL);

            message=NULL;
        }
        if(SDL_Flip(screen) == -1)
        {
            return false;
        }
    }
    //Quit SDL
    SDL_Quit();

    return 0;
}

大熊猫 2007-03-12 19:27 发表评论

C++面试题

大熊猫 — Sat, 10 Mar 2007 14:09:00 GMT

int _tmain( int argc, _TCHAR * argv[])
{
char str1[]        = " abc " ;
char str2[]        = " abc " ;
const char str3[] = " abc " ;
const char str4[] = " abc " ;
const char * str5   = " abc " ;
const char * str6   = " abc " ;

cout << (str1 == str2) << " \n " ;
cout << (str3 == str4) << " \n " ;
cout << (str5 == str6) << " \n " ;
::system( " pause " );
return 0 ;
}

以上会输出什么呢，答案是0,0,1。
前面四个变量都在栈上分配了内存，故内存地址大家都不同，而str5和str6所指字符串在常量区，大家有者一样的地址。

大熊猫 2007-03-10 22:09 发表评论