Hi BrowserUk,

I agree that there really isn't a clean way to do this. I'm not really sure what your primary motivation is though, whether it's efficiency or readability.

One way to reform the problem though is to say that you don't want the range [0,M] inclusive, but actually [0,M+1) without including the end point. This way you can avoid having to treat the last or first segment as special case.

Here is how I would redo your code by creating an intermediate data structure to contain the points

#! perl -slw
use strict;

our $N //= 2;
our $M //= 1e6;

$M++; # No segment contains the upper end point.

my @points = map {int $M * $_ / $N} (0..$N);
my @ranges = map {[$points[$_], $points[$_+1]-1]} (0..$#points-1);

printf "%2d : from %7d to %7d (%7d)\n",
    $_, @{ $ranges[ $_ ] },
    $ranges[ $_ ][ 1 ] - $ranges[ $_ ][ 0 ] + 1
    for 0 .. $#ranges;

__END__

[download]

- Miller

In reply to Re: Split range 0 to M into N non-overlapping (roughly equal) ranges. by wind
in thread Split range 0 to M into N non-overlapping (roughly equal) ranges. by BrowserUk

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.