Data commit

Task/ISBN13-check-digit/F-Sharp/isbn13-check-digit.fs

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+// ISBN13 Check Digit
+open System
+
+let parseInput (input: string) =
+    Seq.map(fun c -> c |> string) input |> Seq.toList |> List.map(fun x -> Int32.Parse x)
+
+[<EntryPoint>]
+let main argv =
+    let isbnnum = parseInput (String.filter (fun x -> x <> '-') argv.[0])
+    // Multiply every other digit by 3
+    let everyOther = List.mapi (fun i x -> if i % 2 = 0 then x * 3 else x) isbnnum
+    // Sum the *3 list with the original list
+    let sum = List.sum everyOther + List.sum isbnnum
+    // If the remainder of sum / 10 is 0 then it's a valid ISBN13
+    if sum % 10 = 0 then
+        printfn "%s Valid ISBN13" argv.[0]
+    else
+        printfn "%s Invalid ISBN13" argv.[0]
+    0