3.1 - sort/searches

Question 1

what is a search algorithm used for?

Answer 1

finding a specific item of data within a data set

Question 2

what is an effective search?

Answer 2

where the search will always find the solution/ target data

Question 3

what is an efficient search?

Answer 3

a search that would find the solution quickly no matter its position in the data set

Question 4

describe the concept of a linear search in terms of finding a piece of paper in a stack of paper

Answer 4

• work from top of stack to bottom

- check each paper along the way

Question 5

state the pros and cons for linear search

Answer 5

pros - easier to code/implement

      - list does not need to be sorted 
      - little memory used to store data 
       - good for small/medium sized lists 

cons -> inefficient/slow on a long list

Question 6

what is the phrase used to describe binary search? —— and ——

Answer 6

divide-and-conquer algorithm

Question 7

describe the concept of a binary search in terms of finding a certain page in a book

Answer 7

• split book in two
• see whether page required is before/after split
• repeat on that side of the data set

Question 8

describe the pros and cons of binary search

Answer 8

pros -> Faster than linear search on a large dataset

cons -> dataset must be sorted before starting
- more complicated to code

Question 9

what does a sort algorithm do?

Answer 9

arranged a dataset in a particular order

Question 10

pros and cons of bubble sort

Answer 10

Pros:

• Easy to code/write
• Does not use much memory

Cons:
- Poor for efficiency (very slow with large list)

Question 11

pros and cons of merge sort

Answer 11

Pros:

• Faster sorting algorithm
• can easily sort longer lists of data

Cons:

• Can be slower for small lists.
• Needs additional memory.
• complicated to code

Question 12

what kind of sort is merge sort?

- describe how it works

Answer 12

divide and conquer algorithm

• break large list into half, then pairs
• then sort out small pairs
• merge them together to one large list

Question 13

how can you measure the efficiency of an algorithm?

Answer 13

• time it takes to run

- amount of space it uses on a computer

Question 14

define a trace table

Answer 14

a technique used to analyse the output of an algorithm on paper

Question 15

compare a binary and linear search

Answer 15

binary search - list has to be ordered
- more efficient

linear- search any array of data type (not ordered)