Y10D/Computer Science GCSE - Algorithms - Linear & Binary

A linear search works by?

• Randomly picking out items in the list until it finds the one it is looking for

• Starts at the beginning and checks each item in sequence until it finds the value it is looking for

• Starts in the middle to see if the value is higher or lower than what is being lookedfor, removing half the list and repeating the process

• Starts at the end and checks each item in the sequence going backwards until itfinds the value it is looking for

How many checks would need to be made to find the number 8, in the list 4,5,9,8,14,20,21?

• 1

• 2

• 3

• 4

What is the best case scenario for finding a value in a linear search?

• It is the first item

• It is the last item

• It is somewhere in the middle

What is the worst case scenario for finding a value in a linear search?

• It is the first item

• It is the last item

• It is somewhere in the middle

• 3

• 4

• 5

• 6

• 3

• 4

• 5

• 6

• To add another item to the list

• To remove an item that has been checked from the list

• To increase the value so that the next item of the list can be checked

• To increase the number of times that the loop will repeat

A binary search works by?

• Randomly picking out items in the list until it finds the one it is looking for

• Starts at the beginning and checks each item in sequence until it finds the value it islooking for

• Starts in the middle to see if the value is higher or lower than what is being looked for, removing half the list and repeating the process

• Starts at the end and checks each item in the sequence going backwards until itfinds the value it is looking for

How many checks would need to be made in a binary search to find the number 5, in the list 4,5,8,9,14,20,21?

• 1

• 2

• 3

• 3

What is the best case scenario for finding a value in a binary search?

• It is the first item

• It is the last item

• It is the middle item