LeetCode – Remove Element (Java)

public class Solution {
    public int removeElement(int[] A, int elem) {
        if(A.length == 0){
            return 0;
        }
        if(A.length == 1){
            if(A[0] == elem){
                return 0;
            }else{
                return 1;
            }
        }
        int i = 0;
        int j = 0;
        while (j < A.length){
            if (A[j] == elem){
                j++;
            }else{
                A[i] = A[j];
                i++;
                j++;
            }
        }
        return i;
    }
}