LeetCode #80. Remove Duplicates from Sorted Array II

class Solution {
    public int removeDuplicates(int[] nums) {
        if (nums.length <= 2) return nums.length;

        int index = 2;

        for (int i = 2; i < nums.length; i++) {
            // Keep element if it's different from the element 2 positions back
            if (nums[i] != nums[index - 2]) {
                nums[index] = nums[i];
                index++;
            }
        }

        return index;
    }
}