finishing leap exercise

exercises/block1/1-leap/example-input

@@ -0,0 +1,10 @@
+1996
+2001
+2020
+1900
+2004
+2100
+1600
+2012
+1800
+2024

exercises/block1/1-leap/example-output

@@ -0,0 +1,10 @@
+True
+False
+True
+False
+True
+False
+True
+True
+False
+True

exercises/block1/1-leap/leap.hs

@@ -2,10 +2,24 @@ import System.IO
 
 isLeapYear :: Int -> Bool
 isLeapYear year -- implement here
+  | year `mod` 400 == 0 = True
+  | year `mod` 100 == 0 = False
+  | year `mod` 4 == 0 = True
+  | otherwise = False
 
 main :: IO ()
 main = do
-    content <- readFile "example-input"
+    inputContent <- readFile "example-input"
+    outputContent <- readFile "example-output"
 
-    print $ isLeapYear 2000
+    let years = map read (lines inputContent) :: [Int]
+        expectedResults = map read (lines outputContent) :: [Bool]
+        actualResults = map isLeapYear years
+        incorrect = [(y, e, a) | (y, e, a) <- zip3 years expectedResults actualResults, e /= a]
+    
+    if null incorrect
+        then putStrLn "All leap year checks passed successfully."
+        else do
+            putStrLn "Errors found in leap year calculation:"
+            mapM_ (\(y, e, a) -> putStrLn $ "Year: " ++ show y ++ ", Expected: " ++ show e ++ ", Got: " ++ show a) incorrect