Given a sorted array, remove the duplicates in-place such that each element appear only once and return the new length.

Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.

Example:

Given nums = [1,1,2],

Your function should return length = 2, with the first two elements of nums
 
 being 1 and 2 respectively.
It doesn‘t matter what you leave beyond the new length.

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

26. Remove Duplicates from Sorted Array（代碼思路新奇）