Sort.java

package at.renehollander.euler;

import java.util.*;

public class Sort {

    static int n = 10;
    static List<Integer> list = new ArrayList<>();

    static final int RED = 0;
    static final int GREEN = 1;
    static final int BLUE = 2;

    public static void main(String[] args) {
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < n; j++) {
                list.add(i);
            }
        }
        Collections.shuffle(list);

        System.out.println(list);

        Queue<Integer> redQueue = new ArrayDeque<>();
        Queue<Integer> greenQueue = new ArrayDeque<>();

        list.clear();
        list.addAll(Arrays.asList(RED, RED, RED, RED, GREEN, GREEN, GREEN, BLUE, BLUE, BLUE, BLUE, GREEN));
        n = 4;

        for (int i = 0; i < n; i++) {
            if (Examine(i) != RED) {
                redQueue.add(i);
            }
            System.out.println(i + ": " + list);
        }
        for (int i = n * 1; i < n * 2; i++) {
            if (Examine(i) == RED) {
                Swap(i, redQueue.poll());
            }
            if (Examine(i) != GREEN) {
                greenQueue.add(i);
            }
            System.out.println(i + ": " + list);
        }
        for (int i = n * 2; i < n * 3; i++) {
            if (Examine(i) == RED) {
                Swap(i, redQueue.poll());
            }
            if (Examine(i) == GREEN) {
                Swap(i, greenQueue.poll());
            }
            System.out.println(i + ": " + list);
        }

    }

    public static int Examine(int i) {
        return list.get(i);
    }

    public static void Swap(int i, int j) {
        int iv = list.get(i);
        int jv = list.get(j);
        list.set(i, jv);
        list.set(j, iv);
    }

}