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Java Array Exercises: Separate 0s on left side and 1s on right side of an array of 0s and 1s in random order

Java Array: Exercise-51 with Solution

Write a Java program to separate 0s on left side and 1s on right side of an array of 0s and 1s in random order.

Pictorial Presentation:

Java Array Exercises: Separate 0s on left side and 1s on right side of an array of 0s and 1s in random order

Sample Solution:

Java Code:

import java.util.Arrays;

public class Main {
    public static void main(String[] args)
    {
        int arr[] = new int[]{ 0, 0, 1, 1, 0, 1, 1, 1,0 };
        int result[];
        System.out.println("Original Array ");
        System.out.println(Arrays.toString(arr));

        int n = arr.length;
 
        result = separate_0_1(arr, n);
        System.out.println("New Array ");
        System.out.println(Arrays.toString(result));
      }
    
    static int [] separate_0_1(int arr[], int n)
     {
        int count = 0;   
     
        for (int i = 0; i < n; i++) {
            if (arr[i] == 0)
                count++;
        }
 
        for (int i = 0; i < count; i++)
            arr[i] = 0;
 
        for (int i = count; i < n; i++)
            arr[i] = 1;
    
         return arr;
     }       
   }

Sample Output:

                                                                              
Original Array 
[0, 0, 1, 1, 0, 1, 1, 1, 0]
New Array 
[0, 0, 0, 0, 1, 1, 1, 1, 1]

Flowchart:

Flowchart: Separate 0s on left side and 1s on right side of an array of 0s and 1s in random order

Visualize Java code execution (Python Tutor):


Java Code Editor:

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Previous: Write a Java program to sort an array of positive integers of a given array, in the sorted array the value of the first element should be maximum, second value should be minimum value, third should be second maximum, fourth second be second minimum and so on.
Next: Write a Java program to separate even and odd numbers of a given array of integers. Put all even numbers first, and then odd numbers.

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Java: Tips of the Day

Array vs ArrayLists:

The main difference between these two is that an Array is of fixed size so once you have created an Array you cannot change it but the ArrayList is not of fixed size. You can create instances of ArrayLists without specifying its size. So if you create such instances of an ArrayList without specifying its size Java will create an instance of an ArrayList of default size.

Once an ArrayList is full it re-sizes itself. In fact, an ArrayList is internally supported by an array. So when an ArrayList is resized it will slow down its performance a bit as the contents of the old Array must be copied to a new Array.

At the same time, it's compulsory to specify the size of an Array directly or indirectly while creating it. And also Arrays can store both primitives and objects while ArrayLists only can store objects.

Ref: https://bit.ly/3o8L2KH