PFP Laboratory 3 - Revision history

Beh01 at 10:57, 29 September 2022

2022-09-29T10:57:42Z

Beh01 at 10:50, 29 September 2022

2022-09-29T10:50:48Z

Beh01 at 10:21, 29 September 2022

2022-09-29T10:21:52Z

Beh01 at 10:16, 29 September 2022

2022-09-29T10:16:11Z

Beh01: Created page with "== High-order functions == * Create a function that takes a string and converts all characters to upper case letters. allToUpper :: String ->..."

2022-09-29T10:11:46Z

Created page with "== High-order functions == * Create a function that takes a string and converts all characters to upper case letters. <syntaxhighlight lang="Haskell">allToUpper :: String ->..."

New page

== High-order functions ==
* Create a function that takes a string and converts all characters to upper case letters.

<syntaxhighlight lang="Haskell">allToUpper :: String -> String</syntaxhighlight>
<syntaxhighlight lang="Haskell" class="myDark">
*Main> allToUpper "aAbc"
"AABC"
</syntaxhighlight>

<div class="mw-collapsible mw-collapsed" data-collapsetext="Hide solution" data-expandtext="Show solution">
<syntaxhighlight lang="Haskell">
import Data.Char

allToUpper :: String -> String
allToUpper xs = [toUpper x |x<-xs]

allToUpper' :: String -> String
allToUpper' xs = map toUpper xs
</syntaxhighlight>
[[File:Tryit.png|center|60px|Try it!|link=https://rextester.com/BVU17842]]
</div>
<div style="clear:both"></div>

* Implement the [https://en.wikipedia.org/wiki/Quicksort <code>quicksort</code>] algorithm. As a pivot use always the first element in the list. For dividing the list, use the function <code>filter</code>.

<div style="float: right"> [[File:Video logo.png|80px|link=https://youtu.be/Sj8cbRv89To]]</div>
<syntaxhighlight lang="Haskell">quicksort :: (Ord a) => [a] -> [a]</syntaxhighlight>
<syntaxhighlight lang="Haskell" class="myDark">
*Main> filter (<5) [1..10]
[1,2,3,4]
</syntaxhighlight>
<syntaxhighlight lang="Haskell" class="myDark">
*Main> quicksort [1,5,3,7,9,5,2,1]
[1,1,2,3,5,5,7,9]
</syntaxhighlight>

<div class="mw-collapsible mw-collapsed" data-collapsetext="Hide solution" data-expandtext="Show solution">
<syntaxhighlight lang="Haskell">
quicksort :: (Ord a) => [a] -> [a]
quicksort [] = []
quicksort (x:xs) = let lp = filter (< x) xs
rp = filter (>= x) xs
in quicksort lp ++ [x] ++ quicksort rp
</syntaxhighlight>
[[File:Tryit.png|center|60px|Try it!|link=https://rextester.com/BVU17842]]
</div>
<div style="clear:both"></div>

← Older revision		Revision as of 10:50, 29 September 2022
Line 1:		Line 1:
		+	== Functions working with lists and tuples ==
		+	Implement following functions:
		+	* Create a function that merge two lists into one list of tuples.
		+
		+	<syntaxhighlight lang="Haskell">zipThem:: [a] -> [b] -> [(a,b)]</syntaxhighlight>
		+	<syntaxhighlight lang="Haskell" class="myDark">
		+	*Main> zipThem [1,2,3] "ABCD"
		+	[(1,'A'),(2,'B'),(3,'C')]
		+	</syntaxhighlight>
		+
		+	<div class="mw-collapsible mw-collapsed" data-collapsetext="Hide solution" data-expandtext="Show solution">
		+	<syntaxhighlight lang="Haskell">
		+	zipThem:: [a] -> [b] -> [(a,b)]
		+	zipThem (x:xs) (y:ys) = (x,y) : zipThem xs ys
		+	zipThem _ _ = []
		+	</syntaxhighlight>
		+	[[File:Tryit.png\|center\|60px\|Try it!\|link=https://rextester.com/BVU17842]]
		+	</div>
		+	<div style="clear:both"></div>
		+
		+	* Create a function that compute Cartesian product of two vectors.
		+
		+	<syntaxhighlight lang="Haskell">dotProduct :: [a] -> [b] -> [(a,b)]</syntaxhighlight>
		+	<syntaxhighlight lang="Haskell" class="myDark">
		+	*Main> dotProduct [1..4] "ABC"
		+	[(1,'A'),(1,'B'),(1,'C'),(2,'A'),(2,'B'),(2,'C'),(3,'A'),(3,'B'),(3,'C'),(4,'A'),(4,'B'),(4,'C')]
		+	</syntaxhighlight>
		+
		+	<div class="mw-collapsible mw-collapsed" data-collapsetext="Hide solution" data-expandtext="Show solution">
		+	<syntaxhighlight lang="Haskell">
		+	dotProduct :: [a] -> [b] -> [(a,b)]
		+	dotProduct [] _ = []
		+	dotProduct (x:xs) ys = tmp ys ++ dotProduct xs ys where
		+	tmp [] = []
		+	tmp (b:bs) = (x,b) : tmp bs
		+
		+	dotProduct' :: [a] -> [b] -> [(a,b)]
		+	dotProduct' xs ys = [(x,y)\|x<-xs, y<-ys]
		+
		+	dotProduct'' :: [a] -> [b] -> [(a,b)]
		+	dotProduct'' x y =
		+	zip (concat (map (replicate (length y)) x))
		+	(concat (replicate (length x) y))
		+	</syntaxhighlight>
		+	[[File:Tryit.png\|center\|60px\|Try it!\|link=https://rextester.com/BVU17842]]
		+	</div>
		+	<div style="clear:both"></div>
		+
		+	* Create a function that computes n-th number in the Fibonacci sequence. The function should use tuples in the solution.
		+
		+	<div style="float: right"> [[File:Video logo.png\|80px\|link=https://youtu.be/Sge0DXXI36k]]</div>
		+	<syntaxhighlight lang="Haskell">fibonacci :: Int -> Int</syntaxhighlight>
		+	<syntaxhighlight lang="Haskell" class="myDark">
		+	*Main> fibonacci 12
		+	144
		+	</syntaxhighlight>
		+
		+	<div class="mw-collapsible mw-collapsed" data-collapsetext="Hide solution" data-expandtext="Show solution">
		+	<syntaxhighlight lang="Haskell">
		+	fibonacci :: Int -> Int
		+	fibonacci n = fst (tmp n) where
		+	fibStep (a,b) = (b,a+b)
		+	tmp 0 = (0,1)
		+	tmp x = fibStep (tmp (x-1))
		+	</syntaxhighlight>
		+	[[File:Tryit.png\|center\|60px\|Try it!\|link=https://rextester.com/BVU17842]]
		+	</div>
		+	<div style="clear:both"></div>
		+
	== High-order functions ==		== High-order functions ==
	* Create a function that takes a string and converts all characters to upper case letters.		* Create a function that takes a string and converts all characters to upper case letters.

@@ Line 113: / Line 113: @@
 </syntaxhighlight>
 [[File:Tryit.png|center|60px|Try it!|link=https://rextester.com/BVU17842]]
 </div>
 <div style="clear:both"></div>