haskell problems 001 -> 006

1 files changed, 23 insertions, 0 deletions

diff --git a/haskell/005-smallest_multiple.hs b/haskell/005-smallest_multiple.hs
new file mode 100644
index 0000000..c395eed
--- /dev/null
+++ b/haskell/005-smallest_multiple.hs
@@ -0,0 +1,23 @@
+-- Smallest multiple
+
+-- Problem 5
+-- 2520 is the smallest number that can be divided by each of the numbers
+-- from 1 to 10 without any remainder.
+
+-- What is the smallest positive number that is evenly divisible by all of
+-- the numbers from 1 to 20?
+
+
+main = do
+    print (first_divisible 2520 [1..20])  -- takes 16s
+
+first_divisible :: Int -> [Int] -> Int
+first_divisible x divs
+    | divisible x divs = x
+    | otherwise = first_divisible (x + 2) divs
+
+divisible :: Int -> [Int] -> Bool
+divisible _ [] = True
+divisible x (d:divs)
+    | x `mod` d /= 0 = False
+    | otherwise = divisible x divs