Remove an element in an array

Question

This is my attempt at this problem, how would I move the 0's to the end of the array? I tried swapping the 0 elements with the end elements and well that wasn't it...

public void removeMiddle()  {
    int pos = values.length/2;
    int n = values.length
    if (n%2 == 0)  {
        int fMid = pos - 1;
        values[pos] = 0;
        values fMid = 0;
    } else  {
        int j = n-1;
        int k = j/2;
        int l = k+1;
        int m = n-l;
        values[m] = 0;
    }
}

Array  =  {5, 2, 7, 9, 1, 3, 2, 4}
result =  [5, 2, 7, 0, 0, 3, 2, 4]
Expected: [5, 2, 7, 3, 2, 4, 0, 0]

Array  =  {5, 2, 7, 9, 1, 3, 2}
result =  [5, 2, 7, 0, 1, 3, 2]
Expected: [5, 2, 7, 1, 3, 2, 0]

If order of other elements is not important, then convert array to collection and sort in descending order. — Sudhanshu Umalkar
– Sudhanshu Umalkar, Commented Apr 8, 2013 at 8:11
@qvd You want to move 0 to the end of array if it contains it ...yes? — Achintya Jha
– Achintya Jha, Commented Apr 8, 2013 at 8:23

NPE · Accepted Answer · 2013-04-08 08:09:46Z

1

Hint: use System.arraycopy() followed by setting the last element to zero.

Alternatively, use a loop.

answered Apr 8, 2013 at 8:09

NPE

503k114 gold badges970 silver badges1k bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Sudhanshu Umalkar · Accepted Answer · 2013-04-08 08:12:30Z

1

Convert array to List, remove zeroes, add them back, and convert list back to array.

answered Apr 8, 2013 at 8:12

Sudhanshu Umalkar

4,2021 gold badge26 silver badges33 bronze badges

4 Comments

qvd Over a year ago

How do you remove an element from a list. values.remove?

Sudhanshu Umalkar Over a year ago

Yes, remove the elements, and add them back and they will get added to the bottom of the list.

qvd Over a year ago

I tried values.remove(position) and it said it couldn't find the variable even after I import java.util.List;

Sudhanshu Umalkar Over a year ago

You can use value to remove the element.

Pratik Singal · Accepted Answer · 2013-04-08 08:45:02Z

0

As said by someone earlier you can Convert array to List, remove zeroes, add them back, and convert list back to array or if you want it from scratch and you know the length of the array then just make one array (say array1) and scan the original array (say array) till the end of the array. If the array contains non-zero number just insert it in the array(array1). Once you are done with scanning just add zeros to the remaining array index.

Hope this might help you.

answered Apr 8, 2013 at 8:45

Pratik Singal

409 bronze badges

Comments

Achintya Jha · Accepted Answer · 2013-04-08 08:55:47Z

0

Try this: I think its easy to understand and implement.

public static void main(String[] args) {
    int[] arr = { 5, 0, 7, 9, 1, 3, 0 };
    int index = 0;
    for (int i = 0; i < arr.length; i++) {
        if (arr[i] != 0) {
            arr[index++] = arr[i];
        }

    }

    Arrays.fill(arr, index, arr.length, 0);
    System.out.println(Arrays.toString(arr));
}

Input:

{ 5, 0, 7, 9, 1, 3, 0 }

Output:

[5, 7, 9, 1, 3, 0, 0]

edited Apr 8, 2013 at 8:55

answered Apr 8, 2013 at 8:27

Achintya Jha

12.9k2 gold badges30 silver badges40 bronze badges

Comments

MaVRoSCy · Accepted Answer · 2013-04-08 08:55:51Z

maybe you can use the LinkedList structure and add all non 0 elements of your array at the start of it and all 0's at the end.

    //initial array
    Integer[] array ={1,2,5,8,0,9,10};

    //converted array to List
    ArrayList<Integer> inputList= new ArrayList<Integer>(Arrays.asList(array));

    //secondary list 
    LinkedList<Integer> outputList = new <Integer>LinkedList();


    for(Integer x:inputList){
        int val= Integer.parseInt(x.toString());
        if(val !=0){
            //add non 0 values at the start
            outputList.addFirst(x);
        }else{
            //add 0's at the end
            outputList.addLast(x);
        }
    }

    //convert back to array
    Integer[] outputArray = new Integer[outputList.size()];
    outputArray = outputList.toArray(outputArray);

Collectives™ on Stack Overflow

Remove an element in an array

5 Answers 5

Comments

4 Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

Comments

4 Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related