80Remove Duplicates from Sorted Array II

题目链接：https://leetcode.com/problems/remove-duplicates-from-sorted-list/

题目：

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.

解题思路：
这题比较简单，维护一个对相同数字的计数值，当计数值大于 2 时，就跳过该元素。
同时，还要维护一个存放当前元素的下标位置，由于前面的元素可能存在计数值大于 2 的情况，遂要把后面的元素往前挪。
特别指出，题目只关心挪动元素后新数组的前 length 个元素

代码实现：

public class Solution {    public int removeDuplicates(int[] nums) {        if(nums == null || nums.length == 0)            return 0;        int n = 1;        int tempN = 1;        int index = 0;        for(int i = 1; i < nums.length; i ++) {            if(nums[i] != nums[i - 1]) {                n ++;                tempN = 1;                nums[++ index] = nums[i];            } else {                if(tempN < 2) {                    n ++;                    nums[++ index] = nums[i];                }                tempN ++;            }        }        return n;    }}

164 / 164 test cases passed.Status: AcceptedRuntime: 2 ms