#! perl -slw
use strict;
use Data::Dumper;

sub x {
    my $aref = shift;
    my( $name, @kids ) = @_;
    unless( @$aref and $aref->[ -1 ]{ name } eq $name ) {
        push @{ $aref }, { name => $name };
    }
    if( @kids ) {
        if( not exists $aref->[ -1 ]{ children } ) {
            $aref->[ -1 ]{ children } = [];
        }
        x( $aref->[ -1 ]{ children }, @kids );
    }
}

my @data;
chomp() and x( \@data, split ' / ', $_ ) while <DATA>;

print Dumper \@data;

__DATA__
one
foo / bar
foo / baz
foo / qux / two
foo / qux / three
foo / qux / four
five