80. Remove Duplicates from Sorted Array II

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.

分析

和26. Remove Duplicates from Sorted Array差不多，只是我增加了一个变量来判断这个数出现的次数，超过2次就略过

代码

class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        if (nums.empty())
            return 0;
        int index=0;
        int times=0;//记录某个数出现次数
        for(int i=1;i<nums.size();i++){
            if (nums[index]!=nums[i]){//不相等 
                nums[++index]=nums[i]; 
                times=0;//不相等，代表是新的数，计数器归0
            }else{//相等 
                times++;
                if (times<2){
                    nums[++index]=nums[i];  
                } 
            } 
        } 
        return index+1;
    }
};