RemoveDuplicates.java

import java.util.Scanner;

class Solution {
    public int removeDuplicates(int[] nums) {
        if (nums.length == 0) return 0;

        int j = 1; // pointer for next unique element

        for (int i = 1; i < nums.length; i++) {
            if (nums[i] != nums[i - 1]) {
                nums[j] = nums[i];
                j++;
            }
        }

        return j; // number of unique elements
    }
}

public class RemoveDuplicates {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter number of elements: ");
        int n = sc.nextInt();

        int[] nums = new int[n];
        System.out.println("Enter " + n + " elements (sorted):");
        for (int i = 0; i < n; i++) {
            nums[i] = sc.nextInt();
        }

        Solution sol = new Solution();
        int newLength = sol.removeDuplicates(nums);

        System.out.println("Array after removing duplicates:");
        for (int i = 0; i < newLength; i++) {
            System.out.print(nums[i] + " ");
        }

        System.out.println("\nNumber of unique elements: " + newLength);

        sc.close();
    }
}