/* file : crossover.c
 * purpose : crossover for the population using two-point
 *           crossover
 */

#include <stdio.h>  /* test use */

#include <stdlib.h>
#include <time.h>


void
crossove(int **popu,int len,int p_size,double rate,int inde,int flag_c)
/* int	**popu;		 pointer to the  population */
/* int 	len;			 length of  vector */
/* int 	p_size;		 population size */
/* double rate;		 rate for crossover */
/* int	inde;			 best fitness index */
{
	extern void twocross(int *,int *,int);
	extern void onecross(int *,int *,int);
	extern void unicross(int *,int *,int);

	int search(int);		/* search the second Kid index */
	void reorder(int *,int, int);		/* reorder the remain individual indexs */

	int i,j;



	int *sg;     /* sg[popsize];	 to store the flag of beibg chosen or not */
	int rno,k1,k2;    /* rno: no. of remaining unchosen individuals */
							/* k1: first chosen kid; k2 : second */

	double prob;

	randomize();

	sg=(int *)calloc(p_size,sizeof(int));

	/* initialization */
	/* at the begining, all have not been selected */
	/* sg[i] store i, and rno=popsize */
	for (i=0;i<p_size;i++)
	{
		sg[i]=i;
	}
	rno=p_size;

	/* begin crossover among population */
	for (i=0;i<(p_size/2+1);i++)
	{
		if (rno>=2) 	/* at least two indivuals remain unchosen */
		{

			j=search(rno);	/* find first kid */
			k1=sg[j];
			rno=rno-1;
			reorder(sg,rno,j);	/* reorder the sign vector */
			j=search(rno); 		/* find second kid */
			k2=sg[j];
			rno=rno-1;
			reorder(sg,rno,j);	/* reorder the sign vector */

			prob=(1.0*random(1000))/1000;
			if (prob<=rate) /* probability for crossover */
			{
				if((k1 !=inde)&&(k2 !=inde))
				{
					switch(flag_c)
					{
						case 0:
							onecross(popu[k1],popu[k2],len);
							break;
						case 1:
							unicross(popu[k1],popu[k2],len);
							break;
						default:
							twocross(popu[k1],popu[k2],len);
					}
				}

			}
		}
	}
	free(sg);
}/* end of crossover.c */


int
search(int si)	/* number of unchosen individuals */
{
	int re;

	re=random(si);
	return(re);
}

void
reorder(int *vec,int si,int ind)
/* int	*vec;		 pointer to the sign vector */
/* int 	si;		 number of unchosen individuals */
/* int	ind;		 selected and need to be removed */
{
	int i;

	if (ind<si)
	{
		for (i=ind;i<si;i++)
		{
			*(vec+i)=*(vec+i+1);
		}
	}
}