Fraction reduction: Difference between revisions

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@@ Line 1,377: / Line 1,377: @@
          , d <- validIntegers xs
          , n < d
-         , gcd n d /= 1
+         , gcd n d /= 1 ]
-         ]
 commonDigits :: Fraction -> [Int]
@@ Line 1,393: / Line 1,392: @@
 findReduction :: Fraction -> [Reduction]
-findReduction z@(n1, d1) = go $ commonDigits z
+findReduction z@(n1, d1) = foldr f [] $ commonDigits z
   where
     decimal = realToFrac n1 / realToFrac d1
+    f x r | decimalWithDrop == decimal = (z, (n2, d2), x) : r
-    go [] = []
+          | otherwise = r
-    go (x:xs)
-      | decimalWithDrop == decimal = (z, (n2, d2), x) : go xs
-      | otherwise = go xs
       where
         n2 = dropDigit x n1
@@ Line 1,423: / Line 1,420: @@
   mapM_ (uncurry displayCount) $ zip groups [2..]
   where
-    groups = [ findReductions [10^1..99]
+    groups = [ findReductions [10^1..99], findReductions [10^2..999]
-             , findReductions [10^2..999]
+             , findReductions [10^3..9999], findReductions [10^4..99999] ]</lang>
-             , findReductions [10^3..9999]
-             , findReductions [10^4..99999] ]</lang>
 {{out}}
 <pre>16/64 = 1/4 by dropping 6