private int partitionQS(int[] arr, int left, int right) {

		int pivotEle = arr[(left + right) / 2];
		while (left <= right) {
			while (arr[left] < pivotEle)
				left++;
			while (arr[right] > pivotEle)
				right--;

			if (left <= right) {
				swap(arr, left, right);
				left++;
				right--;
			}
		}

		return left;
	}