private static void shufflePlayer(Player[] arr)
	{
		for (int i = 0 ; i != arr.length ; ++i) {
			int j = random.nextInt(arr.length - i) + i;
			Player t = arr[i];
			arr[i] = arr[j];
			arr[j] = t;
		}
        

        // set index
        for (int i = 0; i != arr.length; ++i)
            arr[i].index = i;
	}