Digital root: Difference between revisions

This code uses sumDigits from [[Sum_digits_of_an_integer#or_Generically]]

<lang fsharp>

//Find the Digital Root of An Integer - Nigel Galloway: February 1st., 2015

//This code will work with any integer type

let inline digitalRoot N BASE =

let rec root(p,n) =

let s = sumDigits n BASE

if s < BASE then (s,p) else root(p+1, s)

root(LanguagePrimitives.GenericZero<_> + 1, N)

</lang>

{{out}}

<pre>

> digitalRoot 627615 10;;

val it : int * int = (9, 2)

> digitalRoot 39390 10;;

val it : int * int = (6, 2)

> digitalRoot 588225 10;;

val it : int * int = (3, 2)

> digitalRoot 393900588225L 10L;;

val it : int64 * int = (9L, 2)

> digitalRoot 123456789123456789123456789123456789123456789I 10I;;

val it : System.Numerics.BigInteger * int = (9 {IsEven = false;

IsOne = false;

IsPowerOfTwo = false;

IsZero = false;

Sign = 1;}, 2)

</pre>