From e923c84095c01903eeb16f2166733dd0fe407f5a Mon Sep 17 00:00:00 2001
From: Boris Skert <boris.skert@gmail.com>
Date: Sat, 28 Sep 2024 18:54:16 +0200
Subject: [PATCH] Solve 'Sum the nums, sum the sums and sum the nums up to that
 sum' kata

---
 src/NumTheNums.hs      |  6 ++++++
 test/NumTheNumsSpec.hs | 14 ++++++++++++++
 2 files changed, 20 insertions(+)
 create mode 100644 src/NumTheNums.hs
 create mode 100644 test/NumTheNumsSpec.hs

diff --git a/src/NumTheNums.hs b/src/NumTheNums.hs
new file mode 100644
index 0000000..638e85a
--- /dev/null
+++ b/src/NumTheNums.hs
@@ -0,0 +1,6 @@
+module NumTheNums (sumOfSums) where
+
+-- https://www.codewars.com/kata/60d2325592157c0019ee78ed/train/haskell
+
+sumOfSums :: Integer -> Integer
+sumOfSums n = n * (n ^ 5 + 6 * n ^ 4 + 13 * n ^ 3 + 18 * n ^ 2 + 22 * n + 12) `div` 72
diff --git a/test/NumTheNumsSpec.hs b/test/NumTheNumsSpec.hs
new file mode 100644
index 0000000..91459aa
--- /dev/null
+++ b/test/NumTheNumsSpec.hs
@@ -0,0 +1,14 @@
+{-# LANGUAGE NumericUnderscores #-}
+
+module NumTheNumsSpec (spec) where
+
+import NumTheNums (sumOfSums)
+import Test.HUnit (assertEqual)
+import Test.Hspec
+
+spec :: Spec
+spec = do
+  it "example tests" $ do
+    assertEqual "sumOfSums 3" 55 $ sumOfSums 3
+    assertEqual "sumOfSums 5" 630 $ sumOfSums 5
+    assertEqual "sumOfSums 100" 14_740_530_850 $ sumOfSums 100