leetcode 26. Remove Duplicates from Sorted Array

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 in place with constant memory.

For example,
Given input array 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

解：由于是已经排好序的，所以相同的数字只会按照顺序出现，遍历一遍，将不同的数字放在数组的前面并记录长度即可。

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