You're asking for a frequency distribution. Statistics::Descriptive makes very quick work of this (and much more):

    use Statistics::Descriptive;
    
    my @ranges = (19, 29, 39); # 1..19, 20..29, 30..39
    
    my $stat = Statistics::Descriptive::Full->new;
    $stat->add_data( 12, 14, 15, 20, 21 );
    
    my %dist = $stat->frequency_distribution(\@ranges);
    printf " %5d: %4d\n", $_, $dist{$_} for @ranges;

[download]

Output:

    19:    3
    29:    2
    39:    0

[download]
use strict; use warnings; omitted for brevity.

In reply to Re: Perl hit counter for multiple ranges, optimization or options in other languages? by rjt
in thread Perl hit counter for multiple ranges, optimization or options in other languages? by SaktiMonk

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