Algorithm Efficiency
	• Take, for example, the ADTs for the ordered list operation RETRIEVE; – remember, it retrieves a value of the item in the Nth position in the ordered list. – In the array based implementation, the Nth item can be accessed directly (it is stored in position N). This access is INDEPENDENT OF N! – Therefore, RETRIEVE takes the same amount of time to access either the 100th item or the first item in the list. Thus, an array based implementation of RETRIEVE is O(1).