Data commit

Task/Modified-random-distribution/Haskell/modified-random-distribution.hs

@@ -0,0 +1,21 @@
+import System.Random
+import Data.List
+import Text.Printf
+
+modify :: Ord a => (a -> a) -> [a] -> [a]
+modify f = foldMap test . pairs
+  where
+    pairs lst = zip lst (tail lst)
+    test (r1, r2) = if r2 < f r1 then [r1] else []
+
+vShape x = if x < 0.5 then 2*(0.5-x) else 2*(x-0.5)
+
+hist b lst = zip [0,b..] res
+  where
+    res = (`div` sum counts) . (*300) <$> counts
+    counts = map length $ group $
+             sort $ floor . (/b) <$> lst
+
+showHist h = foldMap mkLine h
+  where
+    mkLine (b,n) = printf "%.2f\t%s %d%%\n" b (replicate n '▇') n