public static ArrayList<String> selectNoRecursion(char arr[], int num, boolean print) {
		ArrayList<String> arrayList = new ArrayList<String>();
		int resultCount=0;
		int index = 0;
		int arrLen = arr.length;
		if (arrLen < num) {
			return arrayList;
		}
		int[] tmp = new int[num];
		tmp[index] = 0;
		while (true) {
			if (tmp[index] >= arrLen) {
				if (index == 0) {
					break;
				}
				index--;
				tmp[index]++;
			} else if (index == num - 1) {
				String tmpStr = "";
				for (int i = 0; i < num; i++) {
					tmpStr += arr[tmp[i]];
				}
				resultCount++;
				if(print) {
					System.out.println(resultCount+": "+tmpStr);
				}
				arrayList.add(tmpStr);
				tmp[index]++;
			} else {
				index++;
				tmp[index] = tmp[index - 1] + 1;
			}
		}
		return arrayList;
	}