Path: csiph.com!x330-a1.tempe.blueboxinc.net!newsfeed.hal-mli.net!feeder3.hal-mli.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!border3.nntp.dca.giganews.com!Xl.tags.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local2.nntp.dca.giganews.com!nntp.earthlink.com!news.earthlink.com.POSTED!not-for-mail
NNTP-Posting-Date: Wed, 30 Nov 2011 14:52:48 -0600
Date: Wed, 30 Nov 2011 12:52:43 -0800
From: Patricia Shanahan <pats@acm.org>
User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:8.0) Gecko/20111105 Thunderbird/8.0
MIME-Version: 1.0
Newsgroups: comp.lang.java.programmer
Subject: Re: Verifying a list is alphabetized
References: <722147ec-ab43-4d7c-8b41-32f8705ee7db@i8g2000vbh.googlegroups.com>
In-Reply-To: <722147ec-ab43-4d7c-8b41-32f8705ee7db@i8g2000vbh.googlegroups.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Message-ID: <o8GdnYLFOJU9CkvTnZ2dnUVZ_qqdnZ2d@earthlink.com>
Lines: 29
X-Usenet-Provider: http://www.giganews.com
NNTP-Posting-Host: 70.230.194.31
X-Trace: sv3-MvNcMDU0B7MKtWmyMYMmQsozKnHeExanjvjOfzD5YBHsd2qk0wJnpm2AuzcH4SFEpLoQUEYSZscmDNQ!aI1+R4zPDbzKXmaJ1jUh4VW4r4rBk6JEdZCTKS8seeMScKOiuysP6qCkR4dCIARN6JJBQmceHGwD!J5VJNPpwu34Tb6maQb5zCR0/tNIhiYMasAvbEQaXIliBTA==
X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers
X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly
X-Postfilter: 1.3.40
X-Original-Bytes: 1965
Xref: x330-a1.tempe.blueboxinc.net comp.lang.java.programmer:10376

On 11/30/2011 7:52 AM, laredotornado wrote:
> Hi,
>
> I'm using Java 1.6.  Given a java.util.List of Strings, what is the
> quickest way to verify that the list is sorted in ascending order?

If you just want to test, scan the list comparing consecutive pairs of
elements:

public static <T extends Comparable<? super T>> boolean isOrdered(
     List<T> data) {
   T oldElement = null;
   for (T currentElement : data) {
     if (oldElement != null
         && oldElement.compareTo(currentElement) > 0) {
       return false;
     }
     oldElement = currentElement;
   }
   return true;
}

If you want to achieve sortedness, you are unlikely to save time
compared to just doing the sort unconditionally.

Patricia