Sort the array, then just compare consecutive values. Sorting speed is n*log(n) instead of n^2

b) If you don't mind some numbers reported twice and the values are all somewhat equally distributed over a fixed range you might seperate them into buckets and only compare all the numbers in each bucket. For example if all numbers are between 0.000000 to 9.9999999, you might generate 100 buckets, with the first bucket having all the numbers between 0.0 and 0.11, the second between 0.1 and 0.21 (the buckets have to overlap to catch the edge cases between two buckets). The speed is n+(n/100)^2*100, which might in some cases be lower than the sort solution.

In reply to Re: fastest way to compare numerical strings? by jethro
in thread fastest way to compare numerical strings? by Anonymous Monk

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.