Haskell

Question 1

Dot operator type

Answer 1

(b -> c) -> (a -> b) -> a -> c

Question 2

exOr x y =

Answer 2

(x || y) && not(x && y)

Question 3

Offset between a lowercase character and its uppercase counterpart

Answer 3

32
ord ‘a’ = 97; ord ‘A’ = 65

Question 4

Read and show

Answer 4

Read: convert from a string to a value
Show: Convert from a value to a string

Question 5

C enumeration vs Java enumeration

Answer 5

C: Integers and enum types can be mixed freely
Java: Defines a new type

Question 6

Switch case in Java, C, C++

Answer 6

Default is to fall through. Prevented by ‘break’

Question 7

Switch case in Prolog, C#

Answer 7

Cannot fall through. permitted by ‘next’

Question 8

Evaluate the inline conditional expression: (x % 2 == 0 ? “even” : “odd)

Answer 8

if (x % 2 == 0) {“even”}
else {“odd”}

Question 9

What is an Ivalue in C++

Answer 9

An Ivalue is an expression that yields an object reference

Question 10

T-square evolution algorithm

Answer 10

1. Start with a square
2. At each convex corner, place another square, centered at the corner, with half the side length of the previous square
3. Repeat step 2

Question 11

T-square evolution recursive parameters

Answer 11

Width decreased by 1/2, Step is decreased by 1, Fill the square

Question 12

Functions used on tuples of size 2 (pairs)

Answer 12

‘fst’ to retrieve first element
‘snd’ to retrieve second element

Question 13

Lists in Haskell vs. Arrays in C/C++/Java

Answer 13

Memory in arrays is contiguous;
Any element can be accessed in constant time

Question 14

head :: [a] -> a

Answer 14

Returns the first element in a list

Question 15

tail :: [a] -> [a]

Answer 15

Returns a list with all elements in a list except for the first element

Question 16

take :: Int -> [a] -> [a]

Answer 16

Returns a list with the first n elements in a list

Question 17

drop :: Int -> [a] -> [a]

Answer 17

Returns the list after removing its first n elements

Question 18

length :: [a] -> Int

Answer 18

Returns number of elements in a list

Question 19

: :: a -> [a] -> [a]

Answer 19

Add a single element to the front of a list

Question 20

++ :: [a] -> [a] -> [a]

Answer 20

Join two lists

Question 21

!! :: [a] -> Int -> a

Answer 21

Returns the nth element of a list starting from 0

Question 22

reverse :: [a] -> [a]

Answer 22

Reverse the order of elements

Question 23

zip :: [a] -> [b] -> [(a, b)]

Answer 23

Take a pair of lists into a list of pairs

Question 24

unzip :: [(a, b)] -> ([a], [a])

Answer 24

Take a list of pair into a pair of lists

Question 25

sum :: [Int]/[Float] -> Int/Float

Answer 25

Sum of a numeric list

Question 26

(x:xs)

Answer 26

Splits a list into its head and tail;
x is the head, xs is the tail

Question 27

List Comprehension General form

Answer 27

[Expression involving var | var <- old list, conditions, …, conditions]

Question 28

What is ‘var <- old list’ called

Answer 28

Generator. iterates over the old list, multiple generators can be used

Question 29

Higher order function

Answer 29

A function that takes one or more functions as a parameter and/or returns a function as its result

Question 30

Map general form

Answer 30

map :: (a -> b) -> [a] -> [b];
function (a -> b) is applied to every element in [a] and the result is the new list [b]

Question 31

General form of lambda function

Answer 31

<arg1>…<arg> -> <expression></expression></arg>

Question 32

Filter function

Answer 32

First argument is a predicate (returns a boolean), second argument is a list