use v5.36;<br><br>sub dist($p1, $p2) {<br>    my $dx = $p1->[0] - $p2->[0];<br>    my $dy = $p1->[1] - $p2->[1];<br>    my $dz = $p1->[2] - $p2->[2];<br>    $dx*$dx + $dy*$dy + $dz*$dz<br>}<br><br>my @points = map [/^(\d+),(\d+),(\d+)$/a], readline;<br><br>my @pairs = map {<br>    my $p1 = $points[$_];<br>    my $i = $_;<br>    map $i >= $_ ? () : [$i, $_, dist($p1, $points[$_])], 0 .. $#[url=https://infosec.exchange/tags/points]points[/url]<br>} 0 .. $#[url=https://infosec.exchange/tags/points]points[/url];<br><br>@pairs = sort { $a->[2] <=> $b->[2] } @pairs;<br><br>my %tbd = map +($_ => 1), 0 .. $#[url=https://infosec.exchange/tags/points]points[/url];<br><br>my (@regions, %r_set);<br>my $representative = sub ($p) {<br>    $regions[$p] //= do {<br>        delete $tbd{$p};<br>        $r_set{$p} = 1;<br>        +{ arity => 1 }<br>    };<br>    my $repr = $p;<br>    while (defined(my $next = $regions[$repr]{repr})) {<br>        $repr = $next;<br>    }<br>    while ($p != $repr) {<br>        my $rr = \$regions[$p]{repr};<br>        ($p, $$rr) = ($$rr, $repr);<br>    }<br>    $repr<br>};<br><br>my $merge = sub ($p, $q) {<br>    $p = $representative->($p);<br>    $q = $representative->($q);<br>    return if $p == $q;<br><br>    if ($regions[$p]{arity} > $regions[$q]{arity}) {<br>        ($p, $q) = ($q, $p);<br>    }<br><br>    my $rp = $regions[$p];<br>    my $rq = $regions[$q];<br>    $rp->{repr} = $q;<br>    $rq->{arity} += $rp->{arity};<br>    delete $r_set{$p};<br>};<br><br>for my $p (@pairs) {<br>    $merge->($p->[0], $p->[1]);<br>    if (!%tbd && %r_set == 1) {<br>        say $points[$p->[0]][0] * $points[$p->[1]][0];<br>        last;<br>    }<br>}<br>