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Thread: Eliminating Duplicates in an Array

  1. #1
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    Cool Eliminating Duplicates in an Array

    Write a method to eliminate the duplicate values in the array using the following method header:

    public static int[] eliminateDuplicate(int[] numbers)

    Write a test program that reads in ten integers, invokes the method, and displays the result. Here is the sample run of the program:

    Enter ten numbers: 1 2 3 2 1 6 3 4 5 2
    The distinct numbers are: 1 2 3 6 4 5
    Here is my code:
    import java.util.*;
     
    public class EliminatingDuplicates {
    	public static void main(String[] args) {
    		Scanner input = new Scanner(System.in);
    		System.out.print("Enter ten numbers: ");		
    		int[] numbers = new int[10];		
    		for(int i = 0; i < numbers.length; i++) {
    			int num = input.nextInt();
    		}
    		System.out.println("The distinct numbers are: "); 
    		eliminateDuplicates(numbers);			
     	}
    	public static void eliminateDuplicates(int[] numbers) {
    		for(int i = 0; i < numbers.length; i++) {
    			boolean distinct = true;
    			for(int j = 0; j < i; j++) {
    				if (numbers[i] == numbers[j]) {
    					distinct = false;
    					break;
    				}
    			if (distinct) 
    				System.out.println(numbers[i]);
    			}
    		}
    	}
    }

    My code compiles. However when I run the program, no distinct numbers show up. This is my output.

    Enter ten numbers: 1 2 3 2 1 6 3 4 5 2
    The distinct numbers are:
    What am I doing wrong??


  2. #2
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    Default Re: Eliminating Duplicates in an Array

    I think the problem is here:
    for(int i = 0; i < numbers.length; i++) {
    			int num = input.nextInt();
    		}
    I'm guessing you're trying to fill the array "numbers" with the numbers you input... But instead you used this "int num", you probably meant putting
    numbers[i] = input.nextInt();

  3. The Following User Says Thank You to Henry518 For This Useful Post:

    m2msucks (October 23rd, 2011)

  4. #3
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    Default Re: Eliminating Duplicates in an Array

    Thanks, I fixed up that part of the code. I am able to get numbers to show up after "The distinct numbers are:". However they are not correct. I think there may be something wrong with my eliminateDuplicates method but I'm not sure what it is.

  5. #4
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    Default Re: Eliminating Duplicates in an Array

    There is another much simpler way:
    - Iterate over the list, adding each item to a Set.
    - Since Set does not allow duplicate items, so the result is a set of unique items.

    java exception
    Last edited by hns1984; January 11th, 2012 at 06:53 PM.

  6. #5
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    Default Re: Eliminating Duplicates in an Array

    hi,
    I am also agree that Set should be used for this what duplicate you do not want just use set of that object.

    bean factory
    Last edited by abani; December 18th, 2011 at 01:58 AM.

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