add .gitignore

fix problem12.hs: use scanl1 instead of mapAccumL
eagletmt · May 27, 2009 · 6dc9089 · 6dc9089
1 parent 01f451a
commit 6dc9089
Show file tree

Hide file tree

Showing 2 changed files with 4 additions and 1 deletion.
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1,3 @@
+*.hi
+*.o
+a.out
diff --git a/10-19/problem12.hs b/10-19/problem12.hs
@@ -5,7 +5,7 @@ divisors :: (Integral a) => a -> [a]
 divisors n = concat [x | i <- [1..floor (sqrt (fromIntegral n))], let (q,r) = n `divMod` i, r == 0, let x = if i == q then [i] else [i,q]]
 
 triangles :: (Integral a) => [a]
-triangles = snd $ mapAccumL (\a x -> (a+x, a)) 1 [2..]
+triangles = scanl1 (+) [1..]
 
 main = print $ fromJust $ find (\i -> length (divisors i) > 500) $ triangles