Untitled

package ARRAYS;

import java.util.Arrays;
import java.util.Scanner;

public class SortArrOf012 {

    /**
     * This class Takes an array nums consisting of only 0, 1, or 2. Sort the array in non-decreasing order.
     * The sorting must be done in-place, without making a copy of the original array.
     *
     * Input: nums = [1, 0, 2, 1, 0]
     * Output: [0, 0, 1, 1, 2]
     * Explanation:
     *
     * The nums array in sorted order has 2 zeroes, 2 ones and 1 two
     * Input: nums = [0, 0, 1, 1, 1]
     * Output: [0, 0, 1, 1, 1]
     * Explanation:
     *
     * The nums array in sorted order has 2 zeroes, 3 ones and zero twos
     * Input: nums = [1, 1, 2, 2, 1]
     * Output:
     * [1, 1, 1, 2, 2]
     */

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        System.out.print("ENTER ARR SIZE -> ");
        int size = sc.nextInt();
        System.out.println("ENTER ARR -> ");
        int [] arr = new int[size];

        for (int i = 0; i < size; i++) {
            arr[i] = sc.nextInt();
        }

        System.out.println("Sorted Arr -> " + Arrays.toString(sortElements(arr)));
    }

    public static int [] sortElements(int [] nums) {

        int zeroCount = 0;
        int oneCount = 0;
        int twoCount = 0;

        for (int i = 0; i < nums.length; i++) {
            if (nums[i] == 0) {
                zeroCount++;
            } else if (nums[i] == 1) {
                oneCount++;
            } else {
                twoCount++;
            }
        }
        
        int size = nums.length;
        for (int i = 0; i < zeroCount; i++) {
            nums[i] = 0;
        }

        for (int i = zeroCount; i < size - twoCount; i++) {
            nums[i] = 1;
        }

        for (int i = size-twoCount; i < size; i++) {
            nums[i] = 2;
        }
         return nums;
    }
}