find-cycle ( polygons chain length -- chain )

Vocabulary

project-euler.061

Inputs

polygons	an object
chain	an object
length	an object

Outputs

chain

an object

Definition

USING: kernel sequences ;

IN: project-euler.061

: find-cycle ( polygons chain length -- chain )
    2dup [ length ] dip =
    [ drop nip [ cycle? ] 1guard ] [
        [ dupd links ] dip [ find-cycle ] curry with
        map-find drop
    ] if ;