public static void CC18_2() {//PASS
		//fisher-yates shuffle algorithm
		int N = 10;
		int[] arr = new int[N];
		for (int i = 0; i < N; ++i) arr[i]=i;
		for (int i = 0; i < N; ++i) {
			int idx = i + (int) (Math.random() * (N-i));//(int) will round the number
			System.out.println("index is: " + idx);
			int temp = arr[idx];
			arr[idx] = arr[i];
			arr[i] = temp;
		}
		for (int i = 0; i < N; ++i) System.out.print(arr[i]+"_");
	}