I can't get this to work! (hard to describe in topic) (please read)

Question

My other class, DivideGenes, is supposed to divide the genes created in Genes in half (to create a sperm cell). I do this by
1. copying the array
2. finding random indexes in the array
3. coppying the values of the random indexes to a different array. (this array has twice as little genes, because it is the sperm cell)
The problem that I encounter is making sure that I don't copy an index more then once.
For example, if my original cell's array is
1,0,1,1,1,0,1,0
I don't want it to get the index - 1 - 3 times.
I don't want
1,1,1,1,1,1,0
Know what I mean?
So I tried to do the following:
1. After I copy the value of the random index, I set the value of that index equal to 3.
2. I check, in a while loop, on the next round of the for loop, if the current index of the array is equal to 3.
3. If it is equal to 3, then I set an integer equal to another random value of the array.
4. I check to see if the integer's value is equal to 3 (just in case it chose something that has been chosen already) and if it is, then I use the "continue;" statement to redo this.
5. If the integer's value IS NOT equal to 3, then i set the current index of my new array (the sperm array) equal to the value of the integer.
For some reason this isn't working. When I run the program, it shows me a lot of 3's in the output. In fact, the amount of 3's in the output accumilate as the program goes on (probably because my while loop is not filtering them out of it.)
Here is my code:
public class DivideGenes
    public int badcopy =0;
    boolean[] genes;
    public int[] dgene = new int[250];
    public int tempgene;
    public int integergene[] = new int[501];
    public int geneholder;
    public DivideGenes(boolean[] genes)
        this.genes = genes;
   public int randommath() { //finds a random number
            double tempgene2 = Math.random();
            tempgene2 = tempgene2*100;
            tempgene = (int)tempgene2;
      return tempgene;
    public void randmategenes() //main process
System.out.println("STARTED THE DivideGenes MAIN PROCESS");
      for (int i =0; i <= 500; i++) {
System.out.println("Genes: " + genes[i]);
if (genes[i] == true) {
//converts the boolean array to an integer array
integergene[i] = 1;
else {
integergene[i] = 0;
System.out.println("Intergergene: " + integergene[i]);
for (int i = 0; i < 250; i++) { //creates the sperm cell
while (integergene[i] == 3) {
//this is where the troubles begins
geneholder = integergene[randommath()];
if (geneholder == 3) {
continue;
else {
dgene[i] = geneholder;
break;
dgene[i] = integergene[randommath()];
integergene[tempgene] = 3;
System.out.println("The random gene is " + dgene[i]);
System.out.println("There were " + badcopy + "bad copies");
sorry, its not very well commented. I can't really comment on this , i am afraid that it will look weird.

Answer 1

Thefurly,
If I understood the task correctly, the following code might do it. This is inspiring, please do post similar tasks :)import java.util.*;
class DivideGenes {
     public static final int MAX_GENES = 500;
     private Vector undividedGenes = new Vector(MAX_GENES);
     private int[] dividedGenes = new int[MAX_GENES/2];
     public DivideGenes() {
          startDivision();
     private void startDivision() {
          initGenes();
          divideGenes();
     public void initGenes() {
          Random random = new Random();
          boolean value = false;
          System.out.println("Undivided genes:");
          for(int x = 0; x < MAX_GENES ; x++) {
               value = random.nextBoolean();
               undividedGenes.add(new Integer(value?1:0));
               System.out.print(value?1:0);
     private void divideGenes() {
          Integer nextGene = null;
          int randomIndex = 0;
          int dividedCounter = 0;
          int x = 0;
          System.out.println("\nDivided genes:");
          for(; x < dividedGenes.length; x++) {
               //select a random gene location from the shrinking Vector
               randomIndex = getRandom(0, undividedGenes.size());
               //get the gene. undividedGenes shrinks :), so we'll never get the same one
               nextGene = (Integer)undividedGenes.remove(randomIndex);
               //store the gene's value
               dividedGenes[dividedCounter++] = nextGene.intValue();
          //show divided genes
          for(x = 0; x < dividedGenes.length; x++)
               System.out.print(dividedGenes[x]);
     private static int getRandom(int from, int to) {
          return Math.abs(new Random().nextInt() % to) + from;
     public static void main(String[] args) { new DivideGenes();     }
}Cheers!