Remove Duplicates from Sorted Array II

Follow up for "Remove Duplicates": What if duplicates are allowed at most twice?

Solution

多一个变量记录当前元素出现的次数。

class Solution {
public:
    /**
     * @param A: a list of integers
     * @return : return an integer
     */
    int removeDuplicates(vector<int> &nums) {
        if(nums.empty()) return 0;
        int len = 1;
        int pivot = nums[0];
        int counter = 1;
        for(int i=1; i<nums.size(); i++) {
            if(nums[i] == pivot) {//duplicated, then check counter
                if(counter ==1) {
                    counter++;
                    nums[len++] = nums[i];
                }
            } else {//update pivot
                counter = 1;
                nums[len++] = nums[i];
                pivot = nums[i];
            }
        }
        return len;
    }
};