G'day SaktiMonk,

Welcome to the monastery.

Update: My original solution (now within <spoiler> tags below) didn't take into account uneven sized ranges. I didn't notice that but ++Laurent_R did (see below). Here's a new version that still uses an array (@bins) for the range counts; caches the results of determining the range; and still only uses one iteration per range to output the bin counts. 

$ perl -Mstrict -Mwarnings -e '
    use List::Util qw{first};

    my @input = qw{12 14 15 20 21};
    my @range_ends = qw{19 29 39};
    my (@bins, %range_index_cache);

    sub get_range_index {
        ( first { $_[0] <= $range_ends[$_] } 0 .. $#range_ends ) // @r
+ange_ends;
    }

    for (@input) {
        ++$bins[$range_index_cache{$_} //= get_range_index($_)];
    }

    for (0 .. $#range_ends) {
        printf "%d-%d %d\n" =>
            $_ ? $range_ends[$_ - 1] + 1 : 1, $range_ends[$_], $bins[$
+_] // 0;
    }
'
1-19 3
20-29 2
30-39 0

[download]

Any datapoints beyond the ranges you specify are counted in the last element of @bins.

<Reveal this spoiler or all in this thread>

[Note: If you're using an old version of Perl that doesn't have the // (Logical Defined-Or) operator, you'll need to use the defined function.]

-- Ken

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

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.