public static void main(String[] args) {
    RemoveDuplicates remover = new RemoveDuplicates();
    int[] nums = {1, 1, 2};
    int length = remover.removeDuplicates(nums);
    System.out.println("length = " + length);
}

public int removeDuplicates(int[] nums) {

    if (nums.length == 0) {
        return 0;
    }

    int uniqueIndex = 0; 

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