char MaskPrecConts (nodeXtype n, nodeXtype *tour, signed char k, int *kval, nodeXtype *precConts,
		    unsigned long int *precMaskBefore, unsigned long int *precMaskAfter,
		    unsigned long int *cityLoc, costtype *servTime, costtype *shortMatrix)
{ int c,d,p;

  for (c=0; c<n; c++)
  { cityLoc[tour[c]]=c;
    precMaskBefore[c]=precMaskAfter[c]=0;
  }

  for (p=0; precConts[p]>0; p++)
  { for (c=cityLoc[precConts[p++]]; precConts[p]>0; p+=2)
    { d = cityLoc[precConts[p]];
      if (d==c)
      { printf("How can city %d come before itself?!?!\n",precConts[p]);
        return(0);
      }
      else if (d>c)
      { if (d >= c + kval[c]) /* not feasible with k values */
	{ printf("Eeeek!\n");return(0);
	}
        else
	{ precMaskAfter[c] += 1<<(d-c);
	}
      }
      else /* d<c */
      { if (c < d + kval[d])
	{ precMaskBefore[c] += 1<<(c-d);
	}
        /* else constraint is already enforced with k's */
      }
      if (c > d-k && c < d+k+k && //conditions for smINX to be valid
	  shortMatrix[smINX(d,c,k)]<precConts[p+1]-servTime[d])
      { shortMatrix[smINX(d,c,k)] = precConts[p+1]-servTime[d];
      }
    }
  }
//for(c=0;c<11;c++)
//{for(d=0;d<11;d++)
//{printf("%4d",shortMatrix[smINX(cityLoc[c],cityLoc[d],k)]);
//}printf(" #\n");}
  return(1);
}