algorithms

Question 1

what are the three types of computational thinking and describe them

Answer 1

abstraction- ignoring the specific details deemed irrelevant to the task and only focusing on the important information involved
decomposition- the process of breaking a large problem down into a much smaller one, solving each one, one step at a time
algorithmic- solving the problem in a logical manner whilst taking the appropiate steps.

Question 2

state the two searching algorithms

Answer 2

binary

linear

Question 3

describe a linear search

Answer 3

the algorithm goes through each number on the list, determining whether or not its the number its looking for, untill it reaches the correct number

Question 4

describe a binary search

Answer 4

the algorithm finds the midpoint of an ordered list. if the midpoint is not equal to the number its looking for, it discards one half of the list, dependant on whether or not the number its looking for is smaller or larger than the midpoint. this process of midpoint and discard continues until it has found the desired number

Question 5

state the three types of algorithmic sorting

Answer 5

merge
bubble
insertion

Question 6

describe how a merge sort works

Answer 6

the algorithm keeps halfing the list until it reaches singular values. once this has happened, it begins joining them up again, but this time comparing each value to determine its place in the list

Question 7

describe how a bubble sort works

Answer 7

groups each value into pairs, comparing them and swapping them if necessary. Highest number always end up on the end of the list

Question 8

describe how an insertion sort works

Answer 8

takes the second value of the list and then compares it to the last, determining whether or not to swap them. process continues until the list is completed. End up with two sections of the list: sorted and unsorted on the right

Question 9

what is pseudocode

Answer 9

an informal coding language that cannot be used to code

Question 10

give the flow diagram symbol for each of the following

• start/stop
• decision
• input/output
• process

Answer 10

• oval
• diamond
• parallelogram
• rectangle

Question 11

pseudocode for a linear search

Answer 11

for item in dataset
if item == target then
return true
endif
endfor
return false

Question 12

pros of a binary search

Answer 12

-it’s more efficient than linear

Question 13

cons of a binary search

Answer 13

-data set has to be ordered prior to programme running