Remove Duplicates from Sorted Array II

Follow up for ”Remove Duplicates”: What if duplicates are allowed at most twice?
For example, Given sorted array A = [1,1,1,2,2,3],
Your function should return length = 5, and A is now [1,1,2,2,3]

分析：数组元素最多只能出现两次。

public 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++){
            if (nums[i] != nums[index - 2])
                nums[index++] = nums[i];
            }
            return index;
    }
}