How to retrieve the worst value?

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Replies are listed 'Best First'.
Re: How to retrieve the worst value? by BrowserUk (Patriarch) on Apr 01, 2004 at 08:07 UTC
No need to sort or transfer values to an array `use List::Util qw[ reduce ]; my $worstKey = reduce{ $hash{ $a } < $hash{ $b } ? $a : $b } keys %hash; print "The worst is $worstKey with a time of $hash{ $worstKey } minute +s";` [download] Examine what is said, not who speaks. "Efficiency is intelligent laziness." -David Dunham "Think for yourself!" - Abigail	[reply] [d/l]
Re: How to retrieve the worst value? by davido (Cardinal) on Apr 01, 2004 at 08:05 UTC
You could do something like this: `my $worst; my $max = 0; while ( my ( $key, $value ) = each %hash ) { if ( $value > $max ) { $worst = $key; $max = $value } } print "The worst process is $worst, with a time of $max minutes.\n";` [download] This snippet assumes no two processes will take exactly the same length of time. However, if there are two that take the exact amount of time, only one of them will be shown. This may or may not be important to you. Dave	[reply] [d/l]
Re: How to retrieve the worst value? by pbeckingham (Parson) on Apr 01, 2004 at 13:52 UTC
Turn the hash inside-out, then sort the keys in descending order and pick the first. `my %hash = (processone => 1, processtwo => 0.005, processthree => 3) +; my %hash2 = map {$hash{$_} => $_} keys %hash; my $worst = (reverse sort keys %hash2)[0]; print "the worst process is $hash2{$worst} with a time of $worst min +utes\n";` [download]	[reply] [d/l]
Re: Re: How to retrieve the worst value? by halley (Prior) on Apr 01, 2004 at 16:07 UTC
Why all the excess complexity? `sort { $h{$a} <=> $h{$b} }` should be just fine here. `%hash = (processone => 1, processtwo => 0.005, processthree => 3); @_ = sort { $hash{$a} <=> $hash{$b} } keys %hash; print $_[0], ' => ', $hash{$_[0]}, " (lowest)\n"; print $_[-1], ' => ', $hash{$_[-1]}, " (highest)\n";` [download] -- `[ e d @ h a l l e y . c c ]`	[reply] [d/l] [select]
Re: Re: How to retrieve the worst value? by mce (Curate) on Apr 01, 2004 at 14:13 UTC
Hi, Why create an extra hash? `print +(sort { $a <=> $b } values %hash)[-1];` [download] The sort by default sorts alfanumeric, so in your case 30 is better than 4. --------------------------- Dr. Mark Ceulemans Senior Consultant BMC, Belgium	[reply] [d/l]