/*=================================================            file : operators.c     purpose : messy GA operators    developed : 1991     author : Kalyanmoy Deb     bugfix : Alex Kosorukoff====================================================*/#include "mga.ext"INDV_ID select_pop()/*  determine which selection operator  */{	if (gen < init_select_gen)		return (init_select());	else 	{		if (thresholdingflag)			return(thresholding_select());		else			return(normal_select());	}}INDV_ID select(first, second)INDV_ID first, second;/*  selects the better of first and second  */{	if (oldpop[first].fitness == oldpop[second].fitness) {		if (tiebreakingflag)			return((oldpop[first].chromlen < \				oldpop[second].chromlen) ? first : second);		else 			return(flip(0.5) ? first : second);	}	else if (oldpop[first].fitness > oldpop[second].fitness)	{		return((maximizationflag) ? first : second);	}	else 	{		return((maximizationflag) ? second : first);	}}INDV_ID init_select()/*  tournament selection operator without shuffling  */{	INDV_ID first,second;	if (pick >= popsize-1)		pick = 0;	first = pick;	second = pick + 1;	pick += 2;	return (select(first, second));}INDV_ID normal_select()/*  tournament selection operator with shuffling  */{	INDV_ID first,second;	if (pick >= popsize-1)	{		pick = 0;		shuffle_pop();	}	first = shuffle[pick];	second = shuffle[pick+1];	pick += 2;	return (select(first, second));}INDV_ID thresholding_select()/*  tournament selection operator with thresholding  */{	register int i,j,k;	INDV_ID first, second, fittest, secondid;	int num1, num2, count, temp, threshold;	BOOLEAN flag;	unsigned *rawgn1, *rawgn2;	if (pick >= popsize-1)	{		pick = 0;		shuffle_pop();	}	/*  choose the first individual, default is first  */	fittest = first = shuffle[pick];	rawgn1 = oldpop[first].fullgene;	num1 = oldpop[first].genelen;	for (k=1,flag=0; (k<=shuffle_num && !flag); k++)	{		/*  choose the second individual  */		secondid = pick + k;		/*  if required, scroll to the begining of the array */		if (k >= (popsize - pick))			secondid = k - (popsize - pick);		second = shuffle[secondid];		rawgn2 = oldpop[second].fullgene;		num2 =  oldpop[second].genelen;		/*  count the number of matched genes  */		count = matched_genes(rawgn1, rawgn2);		/*  calculate the threshold value  */		threshold = (num1 * num2);		threshold /= problem_length;		if (count > threshold)		/*  if count > threshold, found a match, perform selection */		{			flag = 1;			temp = shuffle[secondid];			shuffle[secondid] = shuffle[pick + 1];			shuffle[pick + 1] = temp;			fittest = select(first, second);			pick++;		}	}	pick++;	return (fittest);}int matched_genes(rawgn1,rawgn2)unsigned *rawgn1;unsigned *rawgn2;/*  count the number of matched genes  */{	register int i, j;	int num = 0;	unsigned rawgn, mask = 1;	for (i = 0; i < bytesize; i++)	{		/*  get the template of common genes */		rawgn = (rawgn1[i] & rawgn2[i]);		/*  count the number of 1's in the template  */		for (j = 0; j < bytelimit[i]; j++)		{			if (((rawgn >> j) & mask) == 1)				num++;		}	}	return(num);}void cut_and_splice(chr1,chr2)struct INDIVIDUAL chr1,chr2;/*  cut and splice operators  */{	int chr3flag, chr4flag;       /* chr4flag appended -- AK */	struct INDIVIDUAL chr3;	struct INDIVIDUAL chr4;	/*  if first chromosome needs to be cut  */	chr4flag = flip(cut_prob * (chr1.chromlen - 1));   /* AK */	if (chr4flag)	{		cut(&chr1,&chr4);		/* if chr4 is not empty first element in chrom_stack is chr4 */		if (chr4.firstgene != NIL)			push_stack(&chrom_stack,chr4);	}	chr3.firstgene = NIL;	/*  if second chromosome needs to be cut  */        chr3flag = flip(cut_prob * (chr2.chromlen - 1));   /* AK */	if (chr3flag)		cut(&chr2,&chr3);	/*  next element in the chrom_stack is chr2  */	push_stack(&chrom_stack,chr2);	/*  if chr3 is not empty, next element in the stack is chr3  */	if (chr3flag)		/* modified by AK */				/* the zero-length chromosome check  */				/* is no longer needed here */		push_stack(&chrom_stack,chr3);	/*  top most element is chr1  */	push_stack(&chrom_stack,chr1);	/*  check elements in the stack and splice  */	do  {	}   while (test_splice());}BOOLEAN test_splice()/*  splice two members of the stack, send 1 if there is a member left,    0 otherwise  */{	struct INDIVIDUAL chr1,chr2;	/*  get the first member  */	if (pop_stack(&chrom_stack,&chr1))	{		if (flip(splice_prob))		{			/*  check for another member in the stack  */			/*  splice if yes  */			if (pop_stack(&chrom_stack,&chr2))				splice(&chr1,&chr2);		}		push_stack(&newchrom_stack,chr1);		return(1);	}	else		return(0);}void cut(chr1,chr2)struct INDIVIDUAL *chr1,*chr2;/*   cut chr1 into two pieces: chr1, chr2   */{	register int i;	struct GENE *temp;	int cut_site;	char msg[PAGEWIDTH];	temp = (*chr1).firstgene;	/* find out cut site  */	cut_site = rnd(1,(*chr1).chromlen-1);   /* modified -- AK */	/*  cut chr1 at cut_site  */	for (i = 1; i < cut_site; i++)		temp = temp->nextgene;	/*   assign other members of chr1 and chr2  */	(*chr2).firstgene = temp->nextgene;	(*chr2).lastgene = (*chr1).lastgene;	(*chr1).lastgene = temp;	temp->nextgene = NIL;	(*chr2).chromlen = (*chr1).chromlen - cut_site;	(*chr1).chromlen = cut_site;	/*  allocate memory for chr2 fullchrom and fullgene  */	if(!((*chr2).fullchrom = (unsigned *)malloc(bytesize*sizeof(unsigned)))) {		sprintf(msg, "Insufficient memory for fullchrom\n");		print_error(msg);	}	if(!((*chr2).fullgene = (unsigned *)malloc(bytesize*sizeof(unsigned)))) {		sprintf(msg, "Insufficient memory for fullgene\n");		print_error(msg);	}}void splice(chr1,chr2)struct INDIVIDUAL *chr1,*chr2;/*   splice chr1 and chr2 to chr1  */{	/*  chr2 is appended behind chr1  */	(*chr1).lastgene->nextgene = (*chr2).firstgene;	(*chr1).lastgene = (*chr2).lastgene;	(*chr1).chromlen = (*chr1).chromlen + (*chr2).chromlen;	/*  destroy chr2 fullchrom and fullgene */	free((*chr2).fullchrom);	free((*chr2).fullgene);}void mutation(chr)struct INDIVIDUAL *chr;/*  if mutation probabalities are greater than zero, perform mutation  */{	register int i; 	struct GENE *temp;	if ((allelic_mut_prob > 0.0) || (genic_mut_prob > 0.0)) {		temp = (*chr).firstgene;		while (temp != NIL)		{			if (flip(allelic_mut_prob))			/*   perform allelic mutation  */			{				if (temp->allele == 1)					temp->allele = 0;				else 					temp->allele = 1;				allelicmutation++;			}			if (flip(genic_mut_prob))			/*  perform genic mutation  */			{				temp->genenumber = \					genic_mutation(temp->genenumber);				genicmutation++;			}			temp = temp->nextgene;		}	}}GENE_ID genic_mutation(num)GENE_ID num;/*  change the genenumber to other  */{	GENE_ID n;	do {		n = rnd(0, problem_length-1);	}  while (n == num);	return(n);}