package no.nowak.pw.exercises;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;

import javax.swing.text.html.parser.Entity;

public class Exercise7Permutation extends Thread
{

    public static Integer arrayLength;
    public static Integer permuteCount = 0;
    public static Double startTime, endTime, countingTime;

    @Override
    public void run()
    {
        arrayLength = new Integer(Exercise7.getNText());
        startTime = System.nanoTime() * 0.00000001;
        Exercise7.setStartTime(startTime);
        Integer[] arr = new Integer[arrayLength];
        for (int i = 0; i < arrayLength; i++)
        {
            arr[i] = i;
        }
        permute(Arrays.asList(arr), 0);
        endTime = System.nanoTime() * 0.00000001;
        Exercise7.setEndTime(endTime);
        Exercise7.setCountingTime(endTime - startTime);
    }

    private static void permute(List<Integer> arr, int k)
    {
        for (int i = k; i < arr.size(); i++)
        {
            Collections.swap(arr, i, k);
            permute(arr, k + 1);
            Collections.swap(arr, k, i);
        }
        if (k == arr.size() - 1)
        {
            System.out.println(Arrays.toString(arr.toArray()));
            permuteCount++;
        }

        System.out.println(permuteCount);
    }

    public static Integer setPermuteCount()
    {
        return permuteCount;
    }

}