initial commit

63_power_digits.fs

@@ -0,0 +1,23 @@
+module _63
+
+open System
+open common
+
+let powerDigits =
+    let powDigitCount e n =
+        let d = Math.Log10(float n) * float e
+        Math.Floor d + 1.0 |> int
+    
+    let findNthPowerDigits e =
+        let pdc = powDigitCount e
+        allIntegers
+        |> Seq.map (fun i -> (i, pdc i))
+        |> Seq.skipWhile (fun (_,n) -> n < e)
+        |> Seq.takeWhile (fun (_,n) -> n <= e)
+        |> Seq.toArray
+
+    allIntegers |> Seq.skip 1
+    |> Seq.map findNthPowerDigits
+    |> Seq.takeWhile (Seq.isEmpty >> not)
+    |> Seq.collect (fun p -> p)
+    |> Seq.length