80. Remove Duplicates from Sorted Array II

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.

Solution

public class Solution {
    public int removeDuplicates(int[] nums) {
        if (nums == null) return 0;
        int size = nums.length;

        if (size <= 2) return size;

        int total = 2;
        int start = 2;
        while (start < size) {
            if (nums[start] != nums[total-2]) nums[total++] = nums[start];
            start ++;
        }

        return total;
    }
}