Since you are looking for a closest match and not an exact match, you necessarily need to iterate over the target set. To me, that means you probably want to use a hash of arrays, not a hash of hashes -- see perllol for info on differences between the structures.

I don't really follow your example, but as best as I can tell, your search algorithm should look something like 

#!/usr/bin/perl -w
use strict;

my @values = (
    15,
    49,
    51,
    79,
);

my $pos = 50;
my $diff;
my @results;

for my $value (@values) {
    if (not defined $diff or abs($pos - $value) < $diff) {
        $diff = abs($pos - $value);
        @results = $value;
    } elsif (abs($pos - $value) == $diff) {
        push @results, $value;
    }
}

print join "\n", @results;

[download]

Note that there are more efficient search procedures, but this may be good enough before you profile.

In reply to Re: Search a hash for closest match by kennethk
in thread Search a hash for closest match by aquinom

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