按值对多维散列进行排序并显示最高的 [英] Sort multidimensional hash by values and print the highest

问题描述

我有一个存储的多维哈希(%info)，具有以下结构:

I have a stored multidimensional hash (%info) with following structure:

$info{$os}{$id}=$length;

foreach $os (keys %info){   
    foreach $id (keys %{$info{$os}}){
        print "$os $id => " . $info{$os}{$id} ."\n" if (keys %info > 100);
    }
}

这样，我可以读取哈希并仅打印出现次数超过100的那些$os，但是现在我只想打印具有最大$ length(即值)的$id.因此，我想按值对散列进行排序，并仅打印具有最高值的$os和$id.

With this, I can read the hash and print only those $os with more than 100 occurrences, but now I would like to print only the $id with highest $length (i.e., values). So I would like to sort the hash by values and print only $os and $id with highest value.

有帮助吗?

推荐答案

可以使用列表:: Util :: reduce 在每个顶级密钥中获取具有最大值的密钥

Can use List::Util::reduce to get the key with the largest value, within each top-level key

use List::Util qw(reduce);

for my $os (keys %info) { 
    my $id_max_length = reduce { 
        $info{$os}{$a} > $info{$os}{$b} ? $a : $b 
    } keys %{$info{$os}};

    say "$os --> $id_max_length --> $info{$os}{$id_max_length}";
}

---

要在所有键中获得最高价值

---

To get the highest value among all keys

my ($max_os, $max_id) = 
    map { $_->[0], $_->[1] }
    reduce { $info{$a->[0]}{$a->[1]} > $info{$b->[0]}{$b->[1]} ? $a : $b }
    map { [$_, max_id_for_os($_)] } 
    keys %info;

say "$max_os -> $max_id -> $info{$max_os}{$max_id}";

sub max_id_for_os {
    my ($os) = @_; 
    reduce { $info{$os}{$a} > $info{$os}{$b} ? $a : $b } keys %{$info{$os}}
}

或者，也许更简单，在循环中对顶级键进行比较

Or, perhaps simpler, compare in the loop over top-level keys

my ($max_os, $max_id) = do {  # initialize
    my ($os) = keys %info;
    $os, (keys %{$info{$os}})[0];
};

for my $os (keys %info) { 
    my $mid = 
        reduce { $info{$os}{$a} > $info{$os}{$b} ? $a : $b } 
        keys %{$info{$os}};

    ($max_os, $max_id) = ($os, $mid) 
        if $info{$os}{$mid} > $info{$max_os}{$max_id};
}

say "Largest: $max_os -> $max_id -> $info{$max_os}{$max_id}";

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