CODEWITHSUNDEEP
javaarraysarraylistmethodsreturn-value
jlacuna1997
jlacuna1997

Reputation: 11

How to take an arbitrary integer array and return an array with the same integers but no duplicates

I need to write a java method unique that takes an arbitrary integer array and return an array with the same integers but no duplicates. Would I have to create the array inside the unique method ? and Would I have to declare arr1, arr2, and arr3 as well?

public static int[] unique(){
        int [] arr1;
        int [] arr2;
        int [] arr3;

     for(int i= 0; i < arr1.length; i++) {

         }

    } 




    public static void main(String[] args) {
        int[] arr1 = {34, 34, 10, 50, 56, 34, 67, 34};
        int[] arr2 = {23, 100, 5, 56, 67, 10, 10, 10, 34, 67};
        int[] arr3 = {25, 25, 25, 25};

        System.out.println(Arrays.toString(unique(arr1)));
        1
        System.out.println(unique(arr1).length);
        System.out.println(Arrays.toString(unique(arr2)));
        System.out.println(unique(arr2).length);
        System.out.println(Arrays.toString(unique(arr3)));
        System.out.println(unique(arr3).length);
    }

}

Upvotes: 1

Views: 398

Answers (2)

Mohamed Ali RACHID
Mohamed Ali RACHID

Reputation: 3297

From Your question what i understand is : you want to create a method that takes an array as parameter and return another containing no duplicate values of the first array.

So what comes directly to mind is using Set ( which is a collection of non duplicated values).

Here you can solve your problem either by checking Array values manually or using a set : 

public static int[] unique(int [] array){

   Set<Integer> set = new HashSet<>(Arrays.asList(array)); // create a set from your array
   // set now containing non duplicate value 
   return set.toArray(new int[set.size()]); // then convert your set to an array and return it.

}

Upvotes: 0

Doga Oruc
Doga Oruc

Reputation: 816

First, put all the values into a Set<Integer>, which by default don't allow duplicate values, then add all the values you have in your Set<Integer> to an int[] and return it.

public static int[] unique(int[] values) {
   Set<Integer> uniqueValuesSet = new HashSet<>();
   for(Integer value : values) {
      uniqueValuesSet.add(value);
   }
   int i = 0;
   int[] uniqueValuesArray = new int[uniqueValuesSet.size()];
   for(Integer value : uniqueValuesSet) {
      uniqueValuesArray[i++] = value;
   }
   return uniqueValuesArray;
}

Upvotes: 1

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