public class Individu {

    private int value;
    private String code;


    public Individu() {
        //this.value = 0;
    }

    public Individu(int value) {
        super();
        this.value = value;
        this.setCode(value);
    }

    public int getValue() {
        return value;
    }

    public void setValue(int value) {
        this.value = value;
    }

    public String getCode() {
        return code;
    }

    private void setCode(int value) {
        String temp;
        temp = Integer.toBinaryString(value);
        if(temp.length()< 4)
        {
            switch (temp.length())
            {
            case 1 : temp="000" + temp;
            break;
            case 2 : temp="00" + temp;
            break;
            case 3 : temp="0" + temp;
            break;
            }
        }
        this.code=temp;
    }



}



public class Population {

    public static final int numberOfIndividu=4;
    private Individu[] pop;

    public Population() {
        pop=new Individu[numberOfIndividu];
    }



    public Population(Individu[] pop) {
        super();
        this.pop = pop;
    }

    public Individu[] getPop() {
        return pop;
    }

    public void setPop(Individu[] pop) {
        this.pop = pop;
    }

    public void setIndToPop(Individu ind,int index)
    {
        this.pop[index]=ind;
    }

    public Individu get(int index)
    {
        return this.pop[index];
    }


}


import java.util.concurrent.ThreadLocalRandom;


public class Tratement {

    public static final double taux = 0.000001;
    private Population p1=new Population();
    private Population p2=new Population();
    private Population p3=new Population();
    private int indOpt=10;

    public Tratement() {
        // TODO Auto-generated constructor stub

    }

    public Tratement(Population p1) {
        super();
        this.p1=p1;
    }

    public int getIndOpt() {
        return indOpt;
    }

    public Population getP1() {
        return p1;
    }

    public void setP1(Population p1) {
        this.p1 = p1;
    }

    public Population getP2() {
        return p2;
    }

    public void setP2(Population p2) {
        this.p2 = p2;
    }


    public Population getP3() {
        return p3;
    }

    public void setP3(Population p3) {
        this.p3 = p3;
    }

    public double fitness(double val)
    {
        return (1/(val+Math.pow(val, 2)));
    }

    public double probability(int index)
    {
        double sum=0;
        int i;
        for(i=0;i<p1.numberOfIndividu;i++)
        {
            sum=sum + fitness((p1.getPop()[i]).getValue());
        }
        return (fitness((p1.getPop()[index]).getValue())/sum);
    }

    public void getMax()
    {
        System.out.println("Previous max :: " +this.indOpt);
        int indice=0;
        double max=0;
        for(int i=0;i<p1.numberOfIndividu;i++)
        {
            double fit=fitness((p1.getPop()[i]).getValue());
            if( max < fit)
            {
                max = fit;
                indice=i;
            }
        }

        if(max > fitness(this.indOpt) )
        {
            this.indOpt=p1.get(indice).getValue();
        }
        System.out.println("Actual max :: " +this.indOpt);
    }

    public void selection()
    {
        Individu[] ind=new Individu[Population.numberOfIndividu];
        for(int i=0;i<p1.numberOfIndividu;i++)
        {

            int rand=ThreadLocalRandom.current().nextInt(0, 4);
            //System.out.println(rand);
            ind[i]=p1.get(rand);
        }
        this.p2.setPop(ind);;

    }

    public void breeding()
    {
        int index=ThreadLocalRandom.current().nextInt(0, 3);
        Individu[] ind=new Individu[Population.numberOfIndividu];
        String s[]=new String[4];
        for(int i=0;i< Population.numberOfIndividu;i++)
        {
            s[i]=p2.get(i).getCode();
        }
        //System.out.println(index);
        String tmp = s[0];
        s[0] = s[0].substring(0, index+1) + s[3].substring(index+1, s[3].length());
        s[3] = s[3].substring(0, index+1) + tmp.substring(index+1, tmp.length());
        tmp = s[1];
        s[1] = s[1].substring(0, index+1) + s[2].substring(index+1, s[2].length());
        s[2] = s[2].substring(0, index+1) + tmp.substring(index+1, tmp.length());

        //System.out.println(s[0] + " " + s[1] + " " + s[2] + " " + s[3]);

        for(int i=0;i< Population.numberOfIndividu;i++)
        {
            ind[i]=new Individu(Integer.parseInt(s[i], 2));
        }
        this.p3.setPop(ind);;
    }

    public void mutation()
    {
        Individu[] ind=new Individu[Population.numberOfIndividu];
        String s[]=new String[4];
        String tmp;
        double rand;
        for(int i=0;i<Population.numberOfIndividu ; i++)
        {
            tmp="";
            for(int j=0;j<4;j++)
            {
                rand=Math.random();
                if(rand < taux)
                {
                    tmp=tmp + Math.round(rand);
                }
                else
                {
                    tmp=tmp + ((p3.get(i)).getCode()).charAt(j);
                }
            }
            s[i]=tmp;
        }

        for(int i=0;i< Population.numberOfIndividu;i++)
        {
            ind[i]=new Individu(Integer.parseInt(s[i], 2));
        }
        this.p1.setPop(ind);;

    }




}




public class Test {

    public static void main(String[] args) {

        int counter=0;
        Individu ind[]={new Individu(1),new Individu(2),new Individu(5),new Individu(8)};
        Population pop=new Population(ind);
        Tratement tr=new Tratement(pop);


        //System.out.println(tr.probability(0));
        //System.out.println(tr.fitness(1));
        //System.out.println(tr.getIndOpt());

        while(counter < 100 )
        {
            System.out.println(" Iteartion : " + counter);

            tr.getMax();

            tr.selection();

            System.out.println("After Selection");

            for(int i=0;i<4;i++)
            {
                System.out.println(tr.getP2().getPop()[i].getValue() + " -> " + tr.getP2().getPop()[i].getCode());
            }

            tr.breeding();

            System.out.println("After Breeding");

            for(int i=0;i<4;i++)
            {
                System.out.println(tr.getP3().getPop()[i].getValue() + " -> " + tr.getP3().getPop()[i].getCode());
            }

            tr.mutation();


            System.out.println("After Mutation");

            for(int i=0;i<4;i++)
            {
                System.out.println(tr.getP1().getPop()[i].getValue() + " -> " + tr.getP1().getPop()[i].getCode());
            }

            counter++;
        }

        System.out.println(tr.getIndOpt());
    }

}