Remove Duplicates from Sorted Array.cpp

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