EKG sequence convergence: Difference between revisions

=={{header|Perl 6}}==

{{works with|Rakudo Star|2018.04.1}}

<lang perl6>sub infix:<shares-divisors-with> { ($^a gcd $^b) > 1 }

sub next-EKG ( *@s ) {

return first {

@s ∌ $_ and @s.tail shares-divisors-with $_

}, 2..*;

}

sub EKG ( Int $start ) { 1, $start, &next-EKG … * }

sub converge-at ( @ints ) {

my @ekgs = @ints.map: &EKG;

return (2 .. *).first: -> $i {

[==] @ekgs.map( *.[$i] ) and

[===] @ekgs.map( *.head($i).Set )

}

}

say "EKG($_): ", .&EKG.head(10) for 2, 5, 7, 9, 10;

for [5, 7], [2, 5, 7, 9, 10] -> @ints {

say "EKGs of (@ints[]) converge at term {$_+1}" with converge-at(@ints);

}</lang>

{{out}}

<pre>

EKG(2): (1 2 4 6 3 9 12 8 10 5)

EKG(5): (1 5 10 2 4 6 3 9 12 8)

EKG(7): (1 7 14 2 4 6 3 9 12 8)

EKG(9): (1 9 3 6 2 4 8 10 5 15)

EKG(10): (1 10 2 4 6 3 9 12 8 14)

EKGs of (5 7) converge at term 21

EKGs of (2 5 7 9 10) converge at term 45

</pre>