chain-length ( n -- n )

Vocabulary

project-euler.074.private

Inputs

n

an object

Outputs

n

an object

Definition

USING: hash-sets kernel sets ;

IN: project-euler.074.private

: chain-length ( n -- n )
    61 <hash-set>
    [ 2dup ?adjoin ] [ [ digits-factorial-sum ] dip ] while nip
    cardinality ;