Hash Sort Perl Hash Hash

Question

I have a hash structure similar to the following:

KeyA => {
         Key1 => {
                   Key4 => 4
                   Key5 => 9
                   Key6 => 10
                 }
         Key2 => {
                   Key7 => 5
                   Key8 => 9
                 }
        }
KeyB => {
         Key3 => {
                   Key9 => 6
                   Key10 => 3
                 }
        }

I need to print the traversal path through the hash structure and the value at the end of the traversal, so this is sorted by value. For example, for the above hash structure, I need to type:

KeyB Key3 Key10 3
KeyA Key1 Key4  4
KeyA Key2 Key7  5
KeyB Key3 Key9  6
KeyA Key2 Key8  9
KeyA Key1 Key5  9
KeyA Key1 Key6  10

Currently, to solve this problem, I look at the hash structure using nested foreach loops, and create a smooth hash by inserting an element with the key equal to the bypass path (for example, "KeyA Key3 Key10") and a value equal to the value at the end of the bypass path ( for example, 3), then another foreach loop is executed, which sorts the smoothed hash by value.

Is there a more efficient way to do this?

Answer 1

, . , , , "-", . O (n) + O (lg n) + O (n) .

Answer 2

, . , , .

use warnings;
use strict;

sub paths {
    my ($data, $cur_path, $dest) = @_; 
    if (ref $data eq 'HASH') {
        foreach my $key (keys %$data) {
            paths($data->{$key}, [@$cur_path, $key], $dest);
        }   
    } else {
        push @$dest, [$cur_path, $data];
    }   
}

my $data = {
    KeyA => {
        Key1 => { Key4 => 4, Key5 => 9, Key6 => 10 },
        Key2 => { Key7 => 5, Key8 => 9 }
    },
    KeyB => { Key3 => { Key9 => 6, Key10 => 3 } }
};

my $dest = []; 
paths($data, [], $dest);

foreach my $result (sort { $a->[1] <=> $b->[1] } @$dest) {
    print join(' ', @{$result->[0]}, $result->[1]), "\n";
}

Answer 3

, , . ( , , .) :

use strict;
use warnings;

my %hash = (
    KeyA => {
        Key1 => {
            Key4 => 4,
            Key5 => 9,
            Key6 => 10,
        },
        Key2 => {
            Key7 => 5,
            Key8 => 9,
        },
    },
    KeyB => {
        Key3 => {
            Key9 => 6,
            Key10 => 3,
        },
    },
);

my @array;
while (my ($k1, $v1) = each %hash) {
    while (my ($k2, $v2) = each %$v1) {
        while (my ($k3, $v3) = each %$v2) {
            push @array, [$k1, $k2, $k3, $v3];
        }
    }
}

foreach my $x (sort { $a->[-1] <=> $b->[-1] } @array) {
    print join(' ', @$x), "\n";
}

Answer 4

, - (. $; perlvar), .

use strict;
use warnings;
my %hash = (
    KeyA => {
          Key1 => {
                    Key4 => 4,
                    Key5 => 9,
                    Key6 => 10,
                  },
          Key2 => {
                    Key7 => 5,
                    Key8 => 9,
                  }
         },
    KeyB => {
          Key3 => {
                    Key9 => 6,
                    Key10 => 3,
                  },
         },
);

my %fhash = 
   map {
        my @fh;
        foreach my $k2 (keys %{$hash{$_}}) {
                foreach my $k3 (keys %{$hash{$_}{$k2}}) {
                        push @fh, (join($;, $_, $k2, $k3) => $hash{$_}{$k2}{$k3});
                }   
        }
        @fh;
   } keys %hash;



foreach (sort { $fhash{$a} <=> $fhash{$b} } keys %fhash) {
    printf("%s\t%d\n", join("\t", split(/$;/, $_)), $fhash{$_});
}

map/foreach, fhash .

Answer 5

, "". , , . . , .