What is the average number of nodes accessed in search for a particular element in an unordered list? In an ordered list? In an unordered array? In an ordered array? Note that a list could be implemented as a linked structure or within an array.

I found the answer to this question, but I just have another follow-up question that I hope will illuminate something for me.

For all of the ADT implementations except for ordered arrays, the avg number of operations comes to , since the formula is divided by n to provide the average, and the "+1" is discarded because it's a constant factor. This is true for all of the ADTs except ordered arrays. For ordered arrays, performing a binary search algorithm (as opposed to, I guess, a linear one), would come to

My question is: why isn't the constant factor discarded in this case? Or should the answer to the avg number of operations for linear search algorithms be ? Thanks for any help you can offer me.