September Morn Update

Task/Pascals-triangle/Haskell/pascals-triangle-6.hs

@@ -1,5 +1,4 @@
-fac = product . enumFromTo 1
-
-binCoef n k = (fac n) `div` ((fac k) * (fac $ n - k))
-
-pascal n = map (binCoef $ n - 1) [0..n-1]
+pascal :: [[Integer]]
+pascal =
+  (1 : [ 0 | _ <- head pascal])
+  : [zipWith (+) (0:row) row | row <- pascal]

Task/Pascals-triangle/Haskell/pascals-triangle-7.hs

@@ -1,11 +1,2 @@
-*Main> putStr $ unlines $ map unwords $ map (map show) $ pascal 10
-1
-1 1
-1 2 1
-1 3 3 1
-1 4 6 4 1
-1 5 10 10 5 1
-1 6 15 20 15 6 1
-1 7 21 35 35 21 7 1
-1 8 28 56 70 56 28 8 1
-1 9 36 84 126 126 84 36 9 1
+*Pascal> take 5 <$> (take 5 $ triangle)
+[[1,0,0,0,0],[1,1,0,0,0],[1,2,1,0,0],[1,3,3,1,0],[1,4,6,4,1]]

Task/Pascals-triangle/Haskell/pascals-triangle-8.hs

@@ -0,0 +1,5 @@
+fac = product . enumFromTo 1
+
+binCoef n k = (fac n) `div` ((fac k) * (fac $ n - k))
+
+pascal n = map (binCoef $ n - 1) [0..n-1]

Task/Pascals-triangle/Haskell/pascals-triangle-9.hs

@@ -0,0 +1,11 @@
+*Main> putStr $ unlines $ map unwords $ map (map show) $ pascal 10
+1
+1 1
+1 2 1
+1 3 3 1
+1 4 6 4 1
+1 5 10 10 5 1
+1 6 15 20 15 6 1
+1 7 21 35 35 21 7 1
+1 8 28 56 70 56 28 8 1
+1 9 36 84 126 126 84 36 9 1