_80.java

package com.fishercoder.solutions;

import java.util.ArrayList;

/**
 * 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 _80 {

    public int removeDuplicates(int[] nums) {
        int counter = 0;
        int len = nums.length;
        if (len == 0) {
            return 0;
        }
        if (len == 1) {
            return 1;
        }
        if (len == 2) {
            return 2;
        }

        ArrayList<Integer> a = new ArrayList();
        a.add(nums[0]);
        a.add(nums[1]);
        for (int i = 2; i < len; i++) {
            if (nums[i] != nums[i - 1]) {
                a.add(nums[i]);
            } else if (nums[i] != nums[i - 2]) {
                a.add(nums[i]);
            }
        }

        counter = a.size();
        for (int i = 0; i < counter; i++) {
            nums[i] = a.get(i);
        }

        return counter;
    }

}