RemoveDuplicatesII.java

package two_pointers;

/**
 * Created by gouthamvidyapradhan on 20/01/2018.
 * 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 RemoveDuplicatesII {

    /**
     * Main method
     * @param args
     * @throws Exception
     */
    public static void main(String[] args) throws Exception{
        int[] A = {1, 1, 1, 2, 2, 2, 3, 4, 4};
        System.out.println(new RemoveDuplicatesII().removeDuplicates(A));
    }

    public int removeDuplicates(int[] nums) {
        if(nums.length == 0) return 0;
        int j = 0;
        int count = 1;
        for(int i = 1; i < nums.length; i++){
            if(nums[i - 1] == nums[i]){
                count ++;
            } else{
                count = 1;
            }
            if(count == 1 || count == 2){
                j++;
                nums[j] = nums[i];
            }
        }
        return j + 1;
    }

}