LeetCode:Remove Duplicates from Sorted Array II

Problems:

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.

解法一：在Remove Duplicates from sorted Array的基础上加入计数count用来判断重复的次数

class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        if(nums.size()==0) return 0;
        
        int index=0;
        int count=1;
        for(int i=1;i<nums.size();i++)
        {
           if(nums[index]!=nums[i])
           {
               nums[++index]=nums[i];
               count=1;
            }
           else if(nums[index]==nums[i]&&count<=1)
           {
                nums[++index]=nums[i];
                count++;
            }
        
        }
        return index+1;
        
    }
};

解法二：

代码简洁聪明

class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        
        if(nums.size()<=2)  return n;
        
        int index=2;
        for(int i=2;i<nums.size();i++)
        {
                if(nums[i]!=nums[index-2])
                   nums[index++]=nums[i];
         }
                
          return index;      
               
    }
};