initial commit

57.fs

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+module _57
+
+open common
+open Fraction
+open System
+open System.Numerics
+
+let sqrtTwoDigits =
+    let sqrtTwoConvergent d =
+        let rec sqrtTwo = function
+            | 1 -> (2I,1I)
+            | d -> addI (2I,1I) (reciprocalI(sqrtTwo (d - 1)))
+        addI (1I,1I) (reciprocalI(sqrtTwo d))
+
+    let digitCount n =
+        let d = BigInteger.Log10(n)
+        Math.Floor d + 1.0 |> int
+
+    [1..1000]
+    |> List.map sqrtTwoConvergent
+    |> List.map (fun (n,d) -> (digitCount n, digitCount d))
+    |> List.mapi (fun i (n,d) -> i + 1, n > d)
+    |> List.filter (snd >> ((=) true))