queen8Nsa

//----------------------------------------------------------------------------------------------
// Meditor Digital Strategies since 1989.
// www.meditor.hu * meditor_at_meditor_dot_hu
// This file : queenNsa.c
// Created by: Végvári Lajos
// Date      : 2017-sep-07 + 09:24:57
//----------------------------------------------------------------------------------------------
// >> Sol omnibus lucet
//----------------------------------------------------------------------------------------------

#define     NUMBER_OF_QUEENS    8

//----------------------------------------------------------------------------------------------

#include    <stdio.h>
#include    <stdlib.h>
#include    <signal.h>

//----------------------------------------------------------------------------------------------

int                     PermuArray[NUMBER_OF_QUEENS];
unsigned long long int  PermuCount;
unsigned long long int  DancingQueen;

//----------------------------------------------------------------------------------------------
//----------------------------------------------------------------------------------------------

unsigned int IsItDancingQueen(void)
    {unsigned int   ok;
     int            i,j;
     int            dif_ndx,dif_permu;

     ok=0;

     i=0;while(i<NUMBER_OF_QUEENS)
     {j=i+1;while(j<NUMBER_OF_QUEENS)
      {
       dif_ndx      = i-j;
       dif_permu    = PermuArray[i]-PermuArray[j];
       if(abs(dif_ndx)==abs(dif_permu))goto iidq_ext;
       j++;
      }
      i++;
     }ok++;

iidq_ext:;

     return(ok);
    }

//----------------------------------------------------------------------------------------------

void PermuCheck(void)
    {unsigned int   i;

     if(IsItDancingQueen())
     {
      i=0;while(i<NUMBER_OF_QUEENS){printf("%3d",PermuArray[i]);i++;}printf("\n");
      DancingQueen++;
     }

     PermuCount++;
    }
//----------------------------------------------------------------------------------------------
//----------------------------------------------------------------------------------------------

void RS_permutation(unsigned int first_ndx)
    {unsigned int   i;
     unsigned int   tmpui;

     if(first_ndx==NUMBER_OF_QUEENS)PermuCheck();

     else
     {i=first_ndx;while(i<NUMBER_OF_QUEENS)
      {
       // swap
       tmpui=PermuArray[first_ndx];PermuArray[first_ndx]=PermuArray[i];PermuArray[i]=tmpui;
       RS_permutation(first_ndx+1);
       //swap
       tmpui=PermuArray[first_ndx];PermuArray[first_ndx]=PermuArray[i];PermuArray[i]=tmpui;
       i++;
      }
     }
    }

//----------------------------------------------------------------------------------------------
//----------------------------------------------------------------------------------------------

void queen_exit(void)
    {
     exit(0);
    }

//----------------------------------------------------------------------------------------------

void IntBreak(void)
    {char       msg[]="! ^C detected: user interrupt.\n";
     printf(msg);
     queen_exit();
    }

//----------------------------------------------------------------------------------------------

void TermBreak(void)
    {char       msg[]="  - TERM signal detected.\n";
     printf(msg);
     queen_exit();
    }

//----------------------------------------------------------------------------------------------

void NormalExit(void)
    {char       msg[]="  - Normal shutdown.\n";
     printf(msg);
     queen_exit();
    }

//----------------------------------------------------------------------------------------------
//----------------------------------------------------------------------------------------------

int main (int argc,char *argv[])
    {unsigned int   i;

     signal(SIGINT,(void*)&IntBreak);               // set signals
     signal(SIGTERM,(void*)&TermBreak);

     PermuCount=DancingQueen=0;
     i=0;while(i<NUMBER_OF_QUEENS){PermuArray[i]=i;i++;}
     RS_permutation(0);

     NormalExit();
     return(0);
    }

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// End of file.
//----------------------------------------------------------------------------------------------