Write a class ReorderArray with a public method reorder that takes one parameter arr of type int[] and returns the arr such that all zeros should come in front of the arr

Write a class ReorderArray with a public method reorder that takes one parameter arr of type int[] and returns the arr such that all zeros should come in front of the arr.

Assumptions:

1. arr is never null

Here is an example:

Enter no of elements in the arr:
8
Enter elements in the arr seperated by space:
55 0 21 0 63 0 45 0
0
0
0
55
21
63
45

Solution

import java.util.Scanner;
public class ReorderArrayMain{
	public static void main(String[] args){
		Scanner s = new Scanner(System.in);
		System.out.println("Enter no of elements in the arr:");
		int n = s.nextInt();
		int[] arr = new int[n];
		System.out.println("Enter elements in the arr seperated by space:");
		for(int i = 0; i < n; i++)
	    {
			arr[i] = s.nextInt();
	    }
	    ReorderArray rOrder = new ReorderArray();
	    int[] result = rOrder.reorder(arr);
	    for(int j = 0; j < result.length; j++) {
	    System.out.println(result[j]);
	    }
	}

	public int[] reorder(int[] arr) {
		//Write your code here
		
		int size = arr.length;
		int i = size-1, j=size-1;
		
		while(i >= 0){
			if(arr[i] != 0){
				arr[j] = arr[i];
				j--;
			}
			i--;
		}
		
		while(j >= 0){
			arr[j] = 0;
			j--;
		}
		
		return arr;
		
	}
}

Happy Learning – If you require any further information, feel free to contact me.