80. Remove Duplicates from Sorted Array II

1. 问题描述
   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.

2. 解决思路
   很简单的ac了这一道题，但是因为其还要对数组进行改变，我生成了一个临时变量去存储新数组，然后再赋值给旧数组。但是看了别人的解答后觉得这种方法真的好蠢。直接贴大神的代码吧。看了也秒懂。

3. 代码

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