【LeetCode】080. 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.

题解：

Solution 1 

class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        int k = 2;
        int n = nums.size();
        if(n < 3)
            return n;
        int index = 0, cnt = 1;
        for(int i = 1; i < n; ++i){
            if(nums[i] != nums[index]){
                cnt = 1;
                nums[++index] = nums[i];
            } else if(++cnt <= k){
                nums[++index] = nums[i];
            }
        }
        return index + 1;
    }
};

Solution 2 

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

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