From 90d4ccd9858dae97082bb45140e2be3ad27110c1 Mon Sep 17 00:00:00 2001
From: JS <1924550@stud.hs-mannheim.de>
Date: Thu, 6 Feb 2025 11:22:55 +0100
Subject: [PATCH] solutions block 3

---
 solutions/block3/maybe.hs        | 17 +++++++++++++++++
 solutions/block3/zauberschule.hs | 27 +++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 solutions/block3/maybe.hs
 create mode 100644 solutions/block3/zauberschule.hs

diff --git a/solutions/block3/maybe.hs b/solutions/block3/maybe.hs
new file mode 100644
index 0000000..b6a1a3c
--- /dev/null
+++ b/solutions/block3/maybe.hs
@@ -0,0 +1,17 @@
+safeHead :: [a] -> Maybe a
+safeHead [] = Nothing
+safeHead (x:_) = Just x
+
+safeTail :: [a] -> Maybe [a]
+safeTail [] = Nothing
+safeTail (_:xs) = Just xs
+
+safeLast :: [a] -> Maybe a
+safeLast [] = Nothing
+safeLast[x] = Just x
+safeLast (_:xs) = safeLast xs 
+
+safeInit :: [a] -> Maybe [a]
+safeInit [] = Nothing
+safeInit [_] = Just []
+safeInit (x:xs) = fmap ([x] ++) (safeInit xs)
diff --git a/solutions/block3/zauberschule.hs b/solutions/block3/zauberschule.hs
new file mode 100644
index 0000000..49d1db1
--- /dev/null
+++ b/solutions/block3/zauberschule.hs
@@ -0,0 +1,27 @@
+-- 1. Definition der magischen Wesen
+data MagicalCreature = Dragon String Int Int
+                     | Unicorn String Int Int
+                     | Wizard String Int Int
+                    deriving (Show)
+
+-- 2. Beschreibung der magischen Wesen
+describeMagicalCreature :: MagicalCreature -> String
+describeMagicalCreature (Dragon name level experience) = name ++ " ist ein Drache mit Magielevel " ++ show level ++ " und " ++ show experience ++ " Erfahrungspunkten."
+describeMagicalCreature (Unicorn name level experience) = name ++ " ist ein Einhorn mit Magielevel " ++ show level ++ " und " ++ show experience ++ " Erfahrungspunkten."
+describeMagicalCreature (Wizard name level experience) = name ++ " ist ein Zauberer mit Magielevel " ++ show level ++ " und " ++ show experience ++ " Erfahrungspunkten."
+
+-- 3. Kräfte
+class Fighter a where
+  power :: a -> Int
+
+instance Fighter MagicalCreature where
+    power (Dragon _ level experience) = (level + experience) * 3
+    power (Unicorn _ level experience) = (level + experience) * 4
+    power (Wizard _ level experience) = (level + experience) * 5
+
+-- 4. Magisches Duell
+duel :: (Fighter a) => a -> a -> Either String a
+duel fighter1 fighter2
+  | power fighter1 > power fighter2 = Right fighter1
+  | power fighter1 < power fighter2 = Right fighter2
+  | otherwise = Left "Unentschieden!"