Adding Haskell examples (#17)

* Adding binary search example for Haskell

* Adding selection sort example in Haskell

* Adding Haskell examples for chapter 3

* Adding examples for chapter 4

* Adding examples for chapter 5

* Adding git ignore

* Add Haskell example for BFS

02_selection_sort/Haskell/01_selectionsort.hs

@@ -0,0 +1,16 @@
+
+helper :: (Integer, [Integer]) -> Integer -> (Integer, [Integer])
+helper (min, xs) e
+  | min <= e = (min, e : xs)
+  | otherwise = (e, min : xs)
+
+minandrest :: [Integer] -> (Integer, [Integer])
+minandrest (x:xs) = foldl helper (x, []) xs
+
+selectionsort :: [Integer] -> [Integer]
+selectionsort [] = []
+selectionsort xs = min : selectionsort rest
+  where (min, rest) = minandrest xs
+
+-- Usage
+-- selectionsort [1,4,2,3,5,6,0,7,8,9,1,9,0]