Remove Duplicates from Sorted Array II

Description

Follow up for "Remove Duplicates":

What if duplicates are allowed at most twice ?

EXAMPLE:

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

Return length of the new array = 5, an array of [1, 1, 2, 2, 3].

Solution 1.

Since the array is sorted, the same elements must lay next to each other.

Add a variable to count the time that an element appears.

public class Solution {
    public int removeDuplicates(int[] nums) {
        if(nums.length == 0) return 0;
        int j = 0; 
        int cnt = 0;
        for(int i = 1; i < nums.length; i ++) {
            if (nums[i] != nums[j]) {
                nums[++j] = nums[i];
                cnt = 0;
            } else {
                cnt ++;
                if (cnt < 2) {
                    nums[++j] = nums[i];
                }
            }
        }
        return j++;
    }
}

Solution 2. Easy Lines...

.......

public int removeDuplicates(int[] nums) {
    int i = 0;
    for (int n : nums)
        if (i < 2 || n > nums[i-2])
            nums[i++] = n;
    return i;
}