leetcode Remove Duplicates from Sorted Array 双指针

https://leetcode.com/problems/remove-duplicates-from-sorted-array/

class Solution {
public:
int removeDuplicates(vector <int> & nums) {
if(nums.size() == 0)return 0;
int first=1,second=1,pre=nums[0];
while(first < nums.size()) {
if(nums[first] != pre) {
pre=nums[second] = nums[first];
second++;
}
first++;
}
return second;
}
};