my @stack = { name => 'root', level => 0, children => [] };

foreach my $input ( @inputs ) {
    my @pieces = split /\s+\/\s+/, $input;
    my $level  = scalar @pieces;

    my $new_node = { name => pieces[-1], level => $level };

    if ( $level == $stack[-1]{level} ) {
        pop @stack;
    }
    elsif ( $level < $stack[-1]{level} ) {
        pop @stack while ( $level <= $stack[-1]{level} );
    }
    # else top level must be our parent
    push @stack[-1]{children}, $new_node;

    push @stack, $new_node
}