LeetCode - Remove Duplicates from Sorted Array

public class Solution {
    public int removeDuplicates(int[] A) {
        
        java.util.SortedSet<Integer> set = new java.util.TreeSet<>();
        for(int i=0; i<A.length; i++) {
        	set.add(A[i]);
        }
        
        int j = 0;
        for(int i : set) {
        	A[j++] = i;
        }
        
        return set.size();
    }
}