Binary Search

How does a Binary Search Work?

• It splits data in two at the middle point, discarding the half that doesn't contain the search item

• It searches through each item one at a time

• It looks for true or false values in a list

• It splits data into two separate setsand searches them one at a time

How does a Linear/Sequential search work?

• It splits data in two at the middle point, discarding the half that doesn't contain the search item

• It starts the end last item and works backwards, comparing each item in turn

• It starts at the first item and compares each item in turn with the search item

• It splits data into two separate sets and searches them one at a time

Where does a linear/sequential search start?

• At the end of a data set

• In the middle of a data set

• At the start of a data set

• The item before the end of a data set

Where does the Binary search start?

• At the end of a data set

• In the middle of a data set

• The item before the end of a data set

• At the start of a data set

Which of the following is true about binary search?

• The list must be sorted

• The list can be in any order

• It works by dividing the list in half and searching each half separately

• t works by searching one element at a time from the beginning of the list

Which of the following is true about linear/sequential search?

• The list must be sorted

• The list can be in any order

• It works by dividing the list in half and searching each half separately

• t works by searching one element at a time from the beginning of the list

Why must a dataset be sorted in order to do a binary search?

• Because it compares each item one at a time

• Because it is easier to program this

• Because it needs to be able to look for the middle point of the data set

• So that you can used mixed data types

A database contains 800 sorted phone numbers. A binary search is used to locate a particular phone number. What is the maximum number of comparison that could be made for this search?

What is the best case scenario in a linear search?

• The item being searched for is at the end of the list

• The item being searched for is at the start of the list

• The item is not present in the list

• The item being searched for is exactly in the middle of the list

Select the best description to explain what a binary search algorithm is.

• Put the elements in order, check each item in turn.

• Put the elements in order, compare with the middle value, split the list in order and repeat.

• Elements do not need to be in order, check each item in turn.

• Elements do not need to be in order, compare to the middle value, split the list in order and repeat