线性表--80. Remove Duplicates from Sorted Array II

80. Remove Duplicates from Sorted Array II

Description

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

Example

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.

Analysis

class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        int n = nums.size();
        if(n < 2) return n;

        int index = 2;
        for (int i = 2; i < n; i++) {
            if (nums[i] != nums[index - 2]) {
                nums[index++] = nums[i];
            }
        }
        return index;
    }
};