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Groups > comp.lang.java.programmer > #29071

Re: Finding Duplicate Values In An Array List

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On 2014-07-10 19:24, Robert Klemme allegedly wrote:
> On 09.07.2014 16:47, Daniele Futtorovic wrote:
>> Here's another, shorter one:
>>
>> public static void main(String[] ss){
>>    Scanner sc = new Scanner(System.in);
>>    Set<Integer> sieve = new HashSet<Integer>();
>>    List<Integer> stash = new ArrayList<Integer>(20);
>>
>>    while( stash.size() < 20 ){
>>      System.err.printf( "Enter %d more number(s) between 10 and 100:%n",
>> 20 - stash.size() );
>>      String raw = sc.next();
>>
>>      try {
>>        int input = Integer.parseInt(raw);
>>
>>        if( input < 10 || input > 100 ){
>>          System.err.println( "Out of range: " + input );
>>        }
>>        else if( ! sieve.add( input ) ){
>>          System.err.println( "Duplicate: " + input );
>>        }
>>        else {
>>          stash.add( input );
>>          System.err.println( stash );
>>        }
>>      }
>>      catch( NumberFormatException nfex  ){
>>        System.err.println( "Not a number: " + raw );
>>      }
>>    }
> 
> Similar amount of lines, but differently distributed
> 
> package golf;
> 
> import java.util.BitSet;
> import java.util.Scanner;
> 
> public class FiDuWa {
> 
>   private static final int LIMIT = 20;
>   private static final int MIN = 10;
>   private static final int MAX = 100;
> 
>   public static void main(String[] args) {
>     @SuppressWarnings("resource")
>     final Scanner scan = new Scanner(System.in);
>     final StringBuilder stash = new StringBuilder();
>     final BitSet used = new BitSet();
> 
>     while (used.cardinality() < LIMIT) {
>       final int i = Integer.parseInt(scan.next());
> 
>       if (i >= MIN && i <= MAX) {
>         if (!used.get(i)) {
>           if (!used.isEmpty())
>             stash.append(' ');
> 
>           stash.append(i);
>           used.set(i);
>           System.out.println(stash);
>         } else
>           System.err.println("Duplicate: " + i);
>       } else {
>         System.err.println("Not in range: " + i);
>       }
>     }
>   }
> }
> 
> The Java standard library is a remarkable beast and BitSets are probably
> underused.

It sure is and they may be. I reckon they do strongly appeal to
(C-family?) programmers used to bit manipulation. While I personally do
on occasion gladly indulge in the latter, it remains that I find they
lack a bit in heuristics. So while they are great tools, their place
would IMO be deep under the hood.

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Thread

Finding Duplicate Values In An Array List gunitinug@gmail.com - 2014-07-09 02:31 -0700
  Re: Finding Duplicate Values In An Array List Joerg Meier <joergmmeier@arcor.de> - 2014-07-09 11:35 +0200
    Re: Finding Duplicate Values In An Array List gunitinug@gmail.com - 2014-07-09 02:40 -0700
      Re: Finding Duplicate Values In An Array List Jukka Lahtinen <jtfjdehf@hotmail.com.invalid> - 2014-07-09 12:48 +0300
  Re: Finding Duplicate Values In An Array List Daniele Futtorovic <da.futt.news@laposte.net> - 2014-07-09 16:47 +0200
    Re: Finding Duplicate Values In An Array List Robert Klemme <shortcutter@googlemail.com> - 2014-07-10 19:24 +0200
      Re: Finding Duplicate Values In An Array List Daniele Futtorovic <da.futt.news@laposte.net> - 2014-07-12 16:18 +0200
  Re: Finding Duplicate Values In An Array List Roedy Green <see_website@mindprod.com.invalid> - 2014-07-12 20:45 -0700

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