I would use hashes of hashes and then count the number of entries. This is just a simple flat-file to tree generation question, akin to flatfile-to-xml constructor.
#!/usr/bin/perl
print "Hello, World...\n";
use strict;
use Data::Dumper;
my @in = qw/
fruit:apple:cox
fruit:apple:pippin
fruit:apple:granny
fruit:banana:yellow
fruit:banana:green
/;
#make an anonymous hash
my $h = {};
foreach (@in) {
my @a = split ':',$_;
my $branch = shift @a;
my $species = shift @a;
my $breed = shift @a;
$h->{$branch}->{$species}->{$breed} = $h->{$branch}->{$species}->{
+$breed} + 1 || 1;
}
print Dumper($h);
print "there are ".scalar (keys %{$h->{fruit}})." fruit species\n";
print "there are ".scalar (keys %{$h->{fruit}->{apple}})." apple breed
+s\n";
print "there are ".scalar (keys %{$h->{fruit}->{banana}})." banana bre
+eds\n";
print "Good luck with your homework\n";
Returns:
C:\>perl test.pl
Hello, World...
$VAR1 = {
'fruit' => {
'apple' => {
'pippin' => 1,
'cox' => 1,
'granny' => 1
},
'banana' => {
'green' => 1,
'yellow' => 1
}
}
};
there are 2 fruit species
there are 3 apple breeds
there are 2 banana breeds
Good luck with your homework
hackmare.
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