LeetCode 26 - Remove Duplicates from Sorted Array

Description:

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

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.

Note:

Do not allocate extra space for another array, you must do this in place with constant memory.

class Solution {
public:
int removeDuplicates(vector<int>& nums) {
if(nums.empty())
return 0;
int count = 1;
int pre = nums[0];
vector<int>::iterator beg = nums.begin();
for(++beg; beg!=nums.end(); ) {   // 从第二个开始
if(*beg == pre)               // 重复，移除
beg = nums.erase(beg);
else                          // 不重复，更新pre
{
pre = *beg;
++beg;
}
}
return nums.size();
}
};