added haskell solution for problem #5

Author: Matthew Gilliard

teams/mjg-haskell/BrisFunctional/Problem3.hs

@@ -0,0 +1,25 @@
+module BrisFunctional.Problem3
+( problem3
+, testProblem3 )
+where
+
+import Test.HUnit
+
+-- Problem 3
+-- What is the largest prime factor of the number 600851475143 ?
+problem3 :: (Integral a) => a -> a
+problem3 a = recurse a 2
+
+recurse :: (Integral a) => a -> a -> a
+recurse num divisor
+  | num == divisor         = num
+  | num `mod` divisor == 0 = recurse (num `div` divisor) divisor
+  | otherwise              = recurse num (divisor+1)
+
+
+-- test case
+testProblem3 = TestCase $ assertEqual 
+  "Problem 3 answer = 6857"
+  6857
+  ( problem3 600851475143 ) 
+

teams/mjg-haskell/BrisFunctional/Problem5.hs

@@ -0,0 +1,24 @@
+module BrisFunctional.Problem5
+( problem5
+, testProblem5 )
+where
+
+import Test.HUnit
+
+-- Problem 5
+-- What is the smallest positive number that is evenly divisible
+-- by all of the numbers from 1 to 20?
+-- nb 6840 = 20*19*18
+problem5 :: Integer -> Integer
+problem5 a
+  | divides1_20 a = a
+  | otherwise     = problem5 (a+6840)
+  where divides1_20 = (\s -> (all (==True) (map (\t -> s `mod` t == 0) [1..20])))
+
+
+-- test case
+testProblem5 = TestCase $ assertEqual 
+  "Problem 5 answer = 232792560"
+  232792560
+  ( problem5 6840 ) 
+

teams/mjg-haskell/BrisFunctional/ProblemTests.hs

@@ -3,11 +3,13 @@ module BrisFunctional.ProblemTests where
 import BrisFunctional.Problem1
 import BrisFunctional.Problem2
 import BrisFunctional.Problem3
+import BrisFunctional.Problem5
 
 import Test.HUnit
 
 main = runTestTT $ TestList
   [ testProblem1
   , testProblem2
-  , testProblem3 ]
+  , testProblem3
+  , testProblem5 ]