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fen to fen functions

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Uri Blass

Joined: 08 Mar 2006
Posts: 5958
Location: Tel-Aviv Israel

Post subject: Re: fen to fen functions Posted: Thu May 24, 2007 12:52 pm

Alessandro Scotti wrote:

Hi Uri,
yes my code only tries to address the easiest scenario and it simply copies anything that follows the board representation. After all I'm not H. G. and there is a limit to what I can do in four lines of code! Wink

I think we could run an informal contest for the:
1) shortest code (but clean and elegant);
2) shortest and trickiest code (anything goes).
Anyone interested?

No chance in competition
I simply tries to write code that works and I am not a good programmer like you but here is my code.

Note that it does not translate move to make in epd files but only the string of the position

Note that I used your trick of xoring with 0x20 to go from small letters to big letters and the opposite otherwise my code could be longer.

I have a different function to check if the string is legal fen so this certainly can crash on illegal fen.

Code:

char fen1[1024];
char shortfen[10];
char * opp_line(char *rankfen)
{
strcpy(shortfen,rankfen);
unsigned int i;
for (i=0;i<strlen(shortfen);i++)
// if (shortfen[i]>='a'&&shortfen[i]<='z')
//    shortfen[i]+='A'-'a';
// else
//    if (shortfen[i]>='A'&&shortfen[i]<='Z')
//    shortfen[i]+='a'-'A';
if (isalpha(shortfen[i]))
shortfen[i]^=0x20;
return shortfen;
}
char *tranpose_line(char *rankfen)
{
memset(shortfen,0,10);
for( char * e = rankfen+strlen(rankfen) - 1; e >= rankfen; e-- )
shortfen[strlen(shortfen)]=*e;
return shortfen;

}
enum {shortcastlewhite=1,longcastlewhite=2,shortcastleblack=4,longcastleblack=8};

char * translate_fen_1(char *fen)
{
memset(fen1,0,1024);
char tempfen[10];
char tempfen2[10][10];
unsigned int l=strlen(fen);
unsigned int i=0;
int i0;
int j=0;
int cast=0;
while ((i<l)&&(fen[i]==' '))
   i++;
while (fen[i]!=' ')
{
   i0=i;
   while ((fen[i]!='/')&&(fen[i]!=' '))
   i++;
   memset(tempfen,0,10);
   memcpy(tempfen,fen+i0,i-i0+1);
   strcpy(tempfen2[j],opp_line(tempfen));
if (fen[i]=='/')
   i++;
   j++;
}
j--;
strncat(fen1,tempfen2[j],strlen(tempfen2[j]));
fen1[strlen(fen1)-1]='/';

while (j>0)
{
   j--;
   strncat(fen1,tempfen2[j],strlen(tempfen2[j]));
}
fen1[strlen(fen1)-1]=' ';
i++;
while (fen[i]==' ')
   i++;
if ((fen[i]=='w')||(fen[i]=='W'))
fen1[strlen(fen1)]='b';
else
   fen1[strlen(fen1)]='w';
fen1[strlen(fen1)]=' ';
i++;
while (fen[i]==' ')
   i++;
if (fen[i]=='-')
{
   fen1[strlen(fen1)]='-';
   i++;
}
else
{
   while (fen[i]!=' ')
   {
      if (fen[i]=='k')
         cast|=shortcastlewhite;
      if (fen[i]=='q')
         cast|=longcastlewhite;
      if (fen[i]=='K')
         cast|=shortcastleblack;
      if (fen[i]=='Q')
         cast|=longcastleblack;
      i++;
   }
   if (cast&shortcastlewhite)
      fen1[strlen(fen1)]='K';
   if (cast&longcastlewhite)
      fen1[strlen(fen1)]='Q';
   if (cast&shortcastleblack)
      fen1[strlen(fen1)]='k';
   if (cast&longcastleblack)
      fen1[strlen(fen1)]='q';
}
fen1[strlen(fen1)]=' ';
while (fen[i]==' ')
   i++;
if (fen[i]=='-')
   fen1[strlen(fen1)]='-';
else
{
   fen1[strlen(fen1)]=fen[i];
   i++;
   fen1[strlen(fen1)]=9-fen[i];
}
i++;
while (i!=l)
{
   fen1[strlen(fen1)]=fen[i];
   i++;
}

return fen1;
}
char *translate_fen_2(char *fen)
{
unsigned int l=strlen(fen);
unsigned int i=0;
char tempfen[10];
int i0;
int cast=0;
memset(fen1,0,1024);
while ((i<l)&&(fen[i]==' '))
   i++;
while (fen[i]!=' ')
{
   i0=i;
   while ((fen[i]!='/')&&(fen[i]!=' '))
   i++;
   memset(tempfen,0,10);
   memcpy(tempfen,fen+i0,i-i0);
   strcat(fen1,tranpose_line(tempfen));
   fen1[strlen(fen1)]=fen[i];
   if (fen[i]=='/')
      i++;
}
while ((fen[i]==' ')&&(i<l))
   i++;
//correct color
if (i<l)
   fen1[strlen(fen1)]=fen[i];
//correct space after color
fen1[strlen(fen1)]=' ';
i++;
if (fen[i]==' ')
   i++;
if (i<l)
if (fen[i]=='-')
{
   while (i<l)
   {
      fen1[strlen(fen1)]=fen[i];
      i++;
   }
}
else
{
   //castling rights

   while ((fen[i]!=' ')&&(i<l))
   {
      if (fen[i]=='k')
         cast|=longcastleblack;
      if (fen[i]=='q')
         cast|=shortcastleblack;
      if (fen[i]=='K')
         cast|=longcastlewhite;
      if (fen[i]=='Q')
         cast|=shortcastlewhite;
      i++;
   }
   if (cast&shortcastlewhite)
      fen1[strlen(fen1)]='K';
   if (cast&longcastlewhite)
      fen1[strlen(fen1)]='Q';
   if (cast&shortcastleblack)
      fen1[strlen(fen1)]='k';
   if (cast&longcastleblack)
      fen1[strlen(fen1)]='q';
   while (i<l)
   {
      fen1[strlen(fen1)]=fen[i];
      i++;
   }

}
return fen1;

}

Display posts from previous:

Subject	Author	Date/Time
fen to fen functions	Uri Blass	Mon May 21, 2007 10:17 am
Re: fen to fen functions	Alessandro Scotti	Mon May 21, 2007 3:20 pm
Re: fen to fen functions	Reinhard Scharnagl	Mon May 21, 2007 5:10 pm
Re: fen to fen functions	Uri Blass	Tue May 22, 2007 1:21 pm
Re: fen to fen functions	Alessandro Scotti	Tue May 22, 2007 3:46 pm
Re: fen to fen functions	Uri Blass	Tue May 22, 2007 4:24 pm
Re: fen to fen functions	Alessandro Scotti	Tue May 22, 2007 4:46 pm
Re: fen to fen functions	Uri Blass	Thu May 24, 2007 12:52 pm
Re: fen to fen functions	Uri Blass	Thu May 24, 2007 4:51 pm
Re: fen to fen functions	Uri Blass	Thu May 24, 2007 8:13 pm
Re: fen to fen functions	Steffan Westcott	Sat Jun 02, 2007 5:05 pm
Re: fen to fen functions	Dann Corbit	Tue May 22, 2007 6:33 pm
Re: fen to fen functions	Dann Corbit	Mon May 21, 2007 5:48 pm

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