when -1 { return (9,  $result_2 == $result_3 ?? -1 :: 1  }

##</code><code>##

                when 0  { return (12, %ball{12} <=> %ball{0}) }

##</code><code>##

use Test::More tests => 24;
use warnings;

for( 1 .. 12 ) {
    %ball = map { $_ => 1; } 1..12;
    for $d ( -1, +1 ) {
        $ball{$_} = 1 + $d * 0.1;
        is_deeply( [$_, $d], [Find_Odd_Ball()], "($_, $d)" );
    }
}

sub Find_Odd_Ball {
    my $result_1 = $ball{1} + $ball{2} + $ball{3} + $ball{4} <=> $ball{5} + $ball{6} + $ball{7} + $ball{8};
    if( $result_1 == 0 ) {
        my $result_2 = $ball{9} + $ball{10} <=> $ball{1} + $ball{11};
        if( $result_2 == 0 ) {
            return (12, $ball{12} <=> $ball{1});
        } else {
            my $result_3 = $ball{9} <=> $ball{10};
            if( $result_3 == -1 ) {
                return (9,  $result_2 == $result_3 ? -1 : 1 );
            } elsif ($result_3 == 0 ) {
                return (11, $result_2 * -1);
            } else {
                return (10, $result_2 == $result_3 ? 1 : -1 );
            }
        }
    } else {
        my $result_2 = $ball{1} + $ball{2} + $ball{5} <=> $ball{3} + $ball{6} + $ball{10};
        if( $result_2 == -1 ) {
            my $result_3 = $ball{1} <=> $ball{2};
            if( $result_3 == -1 ) {
                return (1,  $result_1);
            } elsif( $result_3 == 0 ) {
                return (6, $result_1 * -1);
            } else {
                return (2, $result_1 * -1);
            }
        } elsif( $result_2 == 0 ) {
            my $result_3 = $ball{7} <=> $ball{8};
            if( $result_3 == -1 ) {
                return (8, $result_1 * -1);
            } elsif( $result_3 == 0 ) {
                return (4, $result_1);
            } else {
                return (7, $result_1 * -1);
            }
        } else {
            return $ball{3} == $ball{10} ? (5, $result_1 * -1) : (3, $result_1);
        }
    }
}