RE: [Dev-C++] reg-Knight's tour problem

[<Ech...@ne...>]

  Message: 8
  From: "Ioannis Vranos" <no...@ya...>
  To: "Dev-C++" <dev...@li...>
  Subject: RE: [Dev-C++] reg-Knight's tour problem
  Date: Thu, 7 Mar 2002 15:20:47 +0200

  > -----Original Message-----
  > From: dev...@li... 
  > [mailto:dev...@li...] On Behalf 
  > Of Mohammed Riyaz
  > Sent: Thursday, March 07, 2002 2:00 PM
  > To: dev...@li...
  > Subject: [Dev-C++] reg-Knight's tour problem
  > 
  > 
  > hey,
  > I had a look at the code sent in. Am new to programming, my 
  > code sux when 
  > compared to that. :D .If any one of you cud fix this code 
  > ,help me out. -Riyaz
  > 
  > #include <iostream.h>
  > #include <stdlib.h>

  Useless
  > #include <process.h>

  Pre-ANSI header file declaration


  > class knight
  >      {
  >      int chess[8][8],location[65][10],denied[64];
  >      int row_loc,pos,i,j;
  >      public:
  >      knight();
  >      void assignment(void);
  >      int value(int);
  >      void refresh(void);
  >      int append(int ,int);
  >      };
  > knight::knight(void)
  >      {
  >      row_loc=-1;
  >      i=j=0;
  >      for(int m=0;m<8;m++)
  >           for(int n=0;n<8;n++)
  >                chess[m][n]=0;
  >      for(int m=0;m<65;m++)
  >           for(int n=0;n<10;n++)
  >                location[m][n]=0;
  >      for(int m=0;m<64;m++)
  >           denied[m]=99;
  >      assignment();
  >      }
  > void knight::assignment(void)
  >      {
  >      chess[i][j]=1;


  Where are i, j defined? Strangely it compiles in MINGW32!!!! (compiler
  defect).

i, j are defined in class knight:

  class knight{
    int chess[8][8],location[65][10],denied[64];
    int row_loc,pos,i,j;                  <-- HERE
  
    public:
    knight();
    void assignment(void);
    int value(int);
    void refresh(void);
    int append(int ,int);
  };


  >      refresh();
  >      pos=value(j+(8*i));
  >      i=pos/8;
  >      j=pos%8;

  >      assignment(); 


  // Recursion never ends!

Since it is tail recursion it could be done in a while loop - once you figure out the exit condition ... while(1) is not good either.

  >      }
  > int knight::value(int val)
  >      {
  >      row_loc++;
  >      int temp=1;
  >      int lock,ii,jj;
  >      location[row_loc][0]=val;
  >      ii=val/8;
  >      jj=val%8;
  >      if(jj==0)
  >           {
  >           if(ii>=1)
  >                {
  >                if(ii>=2)
  >                     {lock=append(val-15,temp);if(lock==0) {temp++;}}
  >                lock=append(val-6,temp);if(lock==0) {temp++;}
  >                }
  >           if(ii<=6)
  >                {
  >                if(ii<=5)
  >                     {lock=append(val+17,temp);if(lock==0) {temp++;}}
  >                lock=append(val+10,temp);if(lock==0) {temp++;}
  >                }
  >           }
  >      if(jj==7)
  >           {
  >           if(ii>=1)
  >                {
  >                if(ii>=2)
  >                     {lock=append(val-17,temp);if(lock==0) {temp++;}}
  >                lock=append(val-10,temp);if(lock==0) {temp++;}
  >                }
  >           if(ii<=6)
  >                {
  >                if(ii<=5)
  >                     {lock=append(val+15,temp);if(lock==0) {temp++;}}
  >                lock=append(val+6,temp);if(lock==0) {temp++;}
  >                }
  >           }
  >      if(jj==1)
  >           {
  >           if(ii>=1)
  >                {
  >                if(ii>=2)
  >                     {
  >                     lock=append(val-15,temp);if(lock==0) {temp++;}
  >                     lock=append(val-17,temp);if(lock==0) {temp++;}
  >                     }
  >                lock=append(val-6,temp);if(lock==0) {temp++;}
  >                }
  >           if(ii<=6)
  >                {
  >                if(ii<=5)
  >                     {
  >                     lock=append(val+17,temp);if(lock==0) {temp++;}
  >                     lock=append(val+15,temp);if(lock==0) {temp++;}
  >                     }
  >                lock=append(val+10,temp);if(lock==0) {temp++;}
  >                }
  >           }
  >      if(jj==6)
  >           {
  >           if(ii>=1)
  >                {
  >                if(ii>=2)
  >                     {
  >                     lock=append(val-15,temp);if(lock==0) {temp++;}
  >                     lock=append(val-17,temp);if(lock==0) {temp++;}
  >                     }
  >                lock=append(val-10,temp);if(lock==0) {temp++;}
  >                }
  >           if(ii<=6)
  >                {
  >                if(ii<=5)
  >                     {
  >                     lock=append(val+17,temp);if(lock==0) {temp++;}
  >                     lock=append(val+15,temp);if(lock==0) {temp++;}
  >                     }
  >                lock=append(val+6,temp);if(lock==0) {temp++;}
  >                }
  >           }
  >      if(jj>1 && jj<6)
  >           {
  >           if(ii>=1)
  >                {
  >                if(ii>=2)
  >                     {
  >                     lock=append(val-17,temp);if(lock==0) {temp++;}
  >                     lock=append(val-15,temp);if(lock==0) {temp++;}
  >                     }
  >                lock=append(val-10,temp);if(lock==0) {temp++;}
  >                lock=append(val-6,temp);if(lock==0) {temp++;}
  >                }
  >           if(ii<=6)
  >                {
  >                if(ii<=5)
  >                     {
  >                     lock=append(val+15,temp);if(lock==0) {temp++;}
  >                     lock=append(val+17,temp);if(lock==0) {temp++;}
  >                     }
  >                lock=append(val+6,temp);if(lock==0) {temp++;}
  >                lock=append(val+10,temp);if(lock==0) {temp++;}
  >                }
  >           }
  >           lock=append(-1,temp);
  >           code:
  >           if(location[row_loc][1]==-1)
  >                {
  >                ii=location[row_loc][0]/8;
  >                jj=location[row_loc][0]%8;
  >                chess[ii][jj]=0;
  >                row_loc--;
  >                if(row_loc<0) {cout<<"NO 
  > SOLUTION";system("pause");exit(0);}
  >                for(int m=1;m<9;m++)
  >                     location[row_loc][m]=location[row_loc][m+1];
  >                goto code;
  >                }
  >           return location[row_loc][1];
  >      }
  > void knight::refresh(void)
  >      {
  >      int l,tot;
  >      l=tot=0;
  >      for(int m=0;m<64;m++)
  >           denied[m]=99;
  >      for(int m=0;m<8;m++)
  >           {
  >           for(int n=0;n<8;n++)
  >                {
  >                if(chess[m][n]==1)
  >                     {
  >                     if(l==63)
  >                          {
  >                          cout<<"RESULT :"<<endl;
  >                          for(int k=0;k<64;k++)
  >                               cout<<denied[k]<<" ";
  >                          system("pause");
  >                          }
  >                     tot=n+(8*m);
  >                     denied[l]=tot;
  >                     l++;
  >                     }
  >                }
  >           }
  >      }
  > int knight::append(int val1,int temp1)
  >      {
  >      int lock=0;
  >      for(int m=0;m<64;m++)
  >           if(denied[m]==val1)
  >                {lock=1;break;}
  >      if(!lock)
  >           location[row_loc][temp1]=val1;
  >      return lock;
  >      }
  > void main()
  >      {knight k;}

  int main()


  Ioannis

  * Ioannis Vranos
  * Programming pages: http://www.noicys.d2g.com
  * Alternative URL: http://run.to/noicys


Evan Hempel
-- 




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