Re: Finding Duplicate Values In An Array List

From:

Daniele Futtorovic <da.futt.news@laposte.net>

Newsgroups:

comp.lang.java.programmer

Date:

Wed, 09 Jul 2014 16:47:56 +0200

Message-ID:

<lpjko2$dbh$1@dont-email.me>

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 );
    }
  }

On 2014-07-09 11:31, gunitinug@gmail.com allegedly wrote:

http://www.dreamincode.net/forums/topic/349987-finding-duplicate-values-in-an-array-list/

My solution:

CLASS Populate:

import java.util.*;

class Populate {

    // goal: populate twenty entries for array.
    // 1. get an input from keyboard an integer value.
    // 2. check its between 10 and 100.
    // 3. check its a duplicate.
    // 4. add to the array.
    // 5. print content of array after each insertion.

    static Scanner kb=new Scanner(System.in);

    int[] array=new int[20];
    int current_size;
    int candidate;

    Populate() {
        current_size=0;
    }

    void generateCandidate() {
        candidate=kb.nextInt();
    }

    void killKB() {
        kb.close();
    }

    int getCandidate() {
        return candidate;
    }

    boolean checkBoundary(int chk) {
        if (chk>=10 && chk<=100) return true;
        else return false;
    }

    // check an integer against all values of the array
    boolean checkIsDuplicate(int chk) {
        for (int i=0; i<current_size; i++) {
            if (chk==array[i]) return true;
        }
        return false;
    }

    void addEntry(int chk) {
        array[current_size]=chk;
        current_size++;
    }

    void print() {
        for (int i=0; i<current_size; i++) {
            System.out.print(array[i]);
            System.out.print(" ");
        }
        System.out.println();
    }
}

CLASS PopulateMain

class PopulateMain {
    public static void main(String[] args) {
        Populate pop=new Populate();

        // how to populate twenty entries?
        int total=0;
        while (total<20) {
            pop.generateCandidate();
            int c=pop.getCandidate();
            if (pop.checkBoundary(c) && !pop.checkIsDuplicate(c)) {
                pop.addEntry(c);
                total++;

                // print only after adding an entry.
                pop.print();
            }
        }
        //pop.killKB();
    }
}

God BLESS YOU!