From 245626cb1e2474f95e63ec3b529c29ddd5e529b8 Mon Sep 17 00:00:00 2001
From: Manuel Thalmann <m@nuth.ch>
Date: Sun, 16 Jun 2024 14:22:43 +0200
Subject: [PATCH] Solve slide tasks

---
 Exercises/exercise-4/Slides.hs | 42 ++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 Exercises/exercise-4/Slides.hs

diff --git a/Exercises/exercise-4/Slides.hs b/Exercises/exercise-4/Slides.hs
new file mode 100644
index 0000000..a845b7a
--- /dev/null
+++ b/Exercises/exercise-4/Slides.hs
@@ -0,0 +1,42 @@
+myMap :: (a -> b) -> [a] -> [b]
+-- myMap f [] = []
+-- myMap f (x : xs) = (f x) : (myMap f xs)
+
+-- inputs: [a, b, c]
+-- desired output: [a', b', c']
+-- non end recursive result:
+-- myMap f [a, b, c]
+-- (f a) : (myMap f [b, c])
+-- (f a) : ((f b) : (myMap f [c]))
+-- (f a) : ((f b) : ((f c) : myMap f []))
+-- (f a) : ((f b) : ((f c) : myMap f []))
+-- (f a) : ((f b) : ((f c) : []))
+-- a' : (b' : (c' : []))
+-- [a', b', c']
+
+-- ((a' : b') : c')
+-- ((f a) : (f b)) : f c
+
+myMap f = realMap []
+  where
+    realMap acc [] = acc
+    realMap acc (x : xs) = realMap (acc ++ [f x]) xs
+
+-- >>> myMap ((+1)) [0, 2, 2, 6]
+-- [1,3,3,7]
+--
+
+
+fakTR :: Integer -> Integer
+fakTR = fakTR_ 1
+  where
+    fakTR_ :: Integer -> Integer -> Integer
+    fakTR_ acc 0 = acc
+    fakTR_ acc n = fakTR_ (n * acc) (n -1)
+
+fakC :: Integer -> Integer
+fakC = fakC_ (const 1)
+  where
+    fakC_ f n
+      | n == 0 = f n
+      | otherwise = fakC_ (\ x -> n * (f x)) $ n - 1
\ No newline at end of file