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).
•