Remove Duplicates from Sorted Array II

Follow up for "Remove Duplicates":
What if duplicates are allowed at most twice?

For example,
Given sorted array nums = [1,1,1,2,2,3],

Your function should return length = 5, with the first five elements of nums being 1, 1, 2, 2 and 3. It doesn't matter what you leave beyond the new length.

 

public class Solution {
    public int removeDuplicates(int[] nums) {
        if (nums.length <= 2) {
        	return nums.length;
        }
        int pre = 1;
        int cur = 2;
        while (cur < nums.length) {
        	if (nums[cur]==nums[pre] && nums[cur]==nums[pre-1]) {
        		cur++;
        	} else {
        		pre++;
        		nums[pre] = nums[cur];
        		cur++;
        	}
        }
        return pre+1;
    }
}